Estimated 1/4 mile - 71 Roadrunner 340 4 speed

[RemCharger]

I've raced some pretty stout 383s, but the 440 is the way to go in that application

 

[Hemirunner]

I raced in the 70's and my best 1/4 mile time was 10.44 with 160 mph. I am unsure about the mph but I always had a high mph. That was with a '68 Road Runner with a 383 bored .60 over, reworked ported and polished heads, milled to far with 13 to 1 compression, tarantula manifold, Holley Dominator, cam and Hooker headers. 11" slicks and a perfectly set up suspension. I lightened to 2,690 pounds which was a key factor. I was a 4 speed with 4.30 gears in a 8 3/4 rear end and I made the 4 speed into a crash box by grinding every other gear off of the 2,3,& 4th main gears. I did not do burnouts and I did not use a line lock. 90-10 shocks in the front, air shocks rear, spring clamps on the front half of the leaf springs to make them a solid "bar", and an adjustable snubber set 1/4" from the floor pan. You have to practice incessantly on your power shifts, shifting with your feet flat on the accelerator. Start slow with your if you do power shifts because if you miss you may blow your engine. Look. This was full race, all out, but you have the choice of duplicating what works, like the suspension. If you drive it on the street the 90-10 shocks mean avoid all potholes, the 5" wide front tires mean driving slow when you turn. Lightening the car means fiberglass hood (which I made). plexiglass windows, no hood hinges, no window mechanisms, no carpet padding, no undercoating, no rear seat, no frills. My time was set at 2,350 feet above sea level, so factored at sea level, it would be lower.

View attachment 1792564

View attachment 1792574

I’m running high 8s at 160 mph so it’s probably a much lower mph but a very cool car nonetheless.

 

[padam]

okay, spending a lot of time researching, now I see something that with my budget may actually benefit me
All 383s are forged crank, so that would mean they should be also all drilled for a 4 speed, right? Most of the 440s I see are all cast crank, so I would need to get a new one
That said, now I don't have to buy a new crank so that it'd work with my transmission, and the crank is just stronger too
How hard is it to push the power level I'm looking out of a 383? Or are the cubes for a 440 just that much more worth it
Anyone with advice here to give, I'm all ears for it

You’ll learn more from doing than asking.

 

[340runner]

You’ll learn more from doing than asking.

Well, today feels negative 8, it's gonna feel like negative 25 when the sun sets in 30 minutes, and I am not going to a junkyard looking for items freezing my balls off, and I don't think anyone is going to meet-up on marketplace. Right now, asking seems like a decent way to learn. I can do more when it warms up and I can actually drive

 

[Curiousyellow71]

You would be better of finding a good used steel crank. Buying a new crank you just as well buy a stroker crank. You don't necessarily need a crank cut for a pilot shaft bearing, look on Brewers website. Occasionally a used steel crank pops up. I got one a few years back from a forum member. Post what your wanting in the wanted section when your ready. Make sure it's a 6 bolt and not a 8 so you can use your flywheel.
Torque is what gets the car moving, which a 440 will make a lot more of. A 383 really isn't much bigger in displacement then your 340, a 360 based 408 would likely be a better fit then a 383.
Its 8 degrees here and feels like -12. Good day to dream and stay warm!

 

[340runner]

You would be better of finding a good used steel crank. Buying a new crank you just as well buy a stroker crank. You don't necessarily need a crank cut for a pilot shaft bearing, look on Brewers website. Occasionally a used steel crank pops up. I got one a few years back from a forum member. Post what your wanting in the wanted section when your ready. Make sure it's a 6 bolt and not a 8 so you can use your flywheel.
Torque is what gets the car moving, which a 440 will make a lot more of. A 383 really isn't much bigger in displacement then your 340, a 360 based 408 would likely be a better fit then a 383.
Its 8 degrees here and feels like -12. Good day to dream and stay warm!

yeah, this engine talk and honestly everything besides tires and rear end for the near future are dreams. People who say practice and doing gotta live in texas or something. I can't do **** driving my car right now, and even if its warm like a couple days ago had a peak, my car would fall away from how much salt they put down after a pile up a couple weeks ago. I haven't even test drove from when I replaced my motor mounts and operating lever for the trans. I tried pulling that rear end yesterday but it got cold to the point of my fingers not having the dexterity to hold the ratchet tight even with gloves

I love dreaming, always got big goals and gotta work towards it.

 

[Phantomx]

Those goals are no problem for a stock stroke 440.
You really have a good set up for the sb to bb swap. Just get a bellhousing like this. I see them used for 400-500 bucks. New price is hard to swallow. It has both engine patterns. It will also keep you safe.

View attachment 1792414

I did some quick googling and everything says this Lakewood 15335 is a big block only bell. It would be cool if there were a dual pattern bell, but I’ve never heard of one and this one doesn’t appear to be.
Travis..

 

[340runner]

I did some quick googling and everything says this Lakewood 15335 is a big block only bell. It would be cool if there were a dual pattern bell, but I’ve never heard of one and this one doesn’t appear to be.
Travis..

I did too, at least i should be able to use the same clutch + flywheel

 

[Curiousyellow71]

My bad.. I was looking at dual pattern bellhousing for a dyno. Probably wishful thinking.

 

[340runner]

I will look again. I may have been looking at a bellhousing for a dyno.

Yeah, I saw the post that I think you deleted, the LKW 77 251 is a dyno bellhousing. I wish they adapted one honestly, but I'll live with getting one whenever I swap engines, i do have a sfi clutch and flywheel already and im not throwing down insane figures so it's probably good for now

 

[Curiousyellow71]

Yeah, I saw the post that I think you deleted, the LKW 77 251 is a dyno bellhousing. I wish they adapted one honestly, but I'll live with getting one whenever I swap engines, i do have a sfi clutch and flywheel already and im not throwing down insane figures so it's probably good for now

Yes, you have good parts at least.

We have a small block 904 transmission behind a 440 in our 65 dart using a adapter plate from A&A transmission so I knew what a plate looks like with both patterns. I saw that lakewood bellhousing with both patterns and did not catch that it was for a dyno and not a 833. To bad it's not for a 833.

 

[340runner]

Yes, you have good parts at least.

We have a small block 904 transmission behind a 440 in our 65 dart using a adapter plate from A&A transmission so I knew what a plate looks like with both patterns. I saw that lakewood bellhousing with both patterns and did not catch that it was for a dyno and not a 833. To bad it's not for a 833.

Yeah, that is too bad, what even goes into it where lakewood couldn't design one for a a833? Looks like it wouldn't be the hardest thing, they got like halfway there the only thing i could think of is it'd be hard to seal up the mating surface between engine and bellhousing

 

[ROYSTOLL2]

Dont worry,

I know what's in there, this will be 3 times in 6 months i replace the mounts, I somehow had a rubber mount last me 1 hit and it broke. I'm replacing them with solids that I have in my house because the mancini poly mounts broke too. I'm getting tired, replacing the mounts with headers are a pain in the ***

Just an idea. You could put in a torque strap that is just barely loose. That way the rubber won't stretch enough to break. If you put in solid mounts and drive it on the street it will rattle your teeth

 

[340runner]

Just an idea. You could put in a torque strap that is just barely loose. That way the rubber won't stretch enough to break. If you put in solid mounts and drive it on the street it will rattle your teeth

Too late, at the time i posted i had them already in the house and now they're in the car. Also, all of that stuff is expensive, solids are substantially cheaper.

It's also a 4 speed so I don't want any twist at all

 

[70bigblockdodge]

Well, that's why I use the mcleod clutch kit and flywheel I do, I have a street extreme and the steel flywheel, it was about 800$

Very good carry on. McLeod is all I've ever used, it's all they do, made in USA, pretty much sums it up.
As far as holes in crankshaft for pilot bushing. You can always cut ~3/4" off the input shaft and use the larger pilot bearing from a early '90s pick up truck. It is better, bigger, longer lasting than the old oilite bushings. It fits in the torque converter register closer to the clutch plate. IMO just a better design in general. You will get the push back about making a permanent mod to a original trans , but it is hidden and IMO along the same lines as oversized forged pistons. Needs to be done to assemble and is a improved part, plus if someone for whatever reason wanted it to go back to factory (why) they could always buy a new input shaft for trans.

 

[Hemirunner]

Just an idea. You could put in a torque strap that is just barely loose. That way the rubber won't stretch enough to break. If you put in solid mounts and drive it on the street it will rattle your teeth

I have an aluminum motor plate. Drive it all over. It’s slightly more vibration but all my teeth are intact

 

[RemCharger]

^^^^ lol worst case is a few trim screws worked loose

 

[Budnicks]

Fill your library before you fill your garage,
words to live by, read get educated on how an engine really works
what it takes to make a chassis work
Mopar Performance has a crapload of books to do all of it
already spelled out for the most part for you, they did it already
you don't need to reinvent the wheel again, they already did it

you're already handicapping yourself by going with a manual trans
I won't even try to talk you out of it, your stuck on it, so deal with it
you'll learn sooner or later after breaking a bunch of stuff
I know it's fun, I've had many fast cars with clutches...

make a plan & stick with it
don't go all over the map & get lost in a number
it will cost you a lot less than experimenting with crappy combos
the experts are out there, a phone call (talk to a pro on each aspect) or website away
I'd stay away from e-mail **** facebook, Instagram
the venders will rarely respond, consistently or repeatedly especially after a sale, for tech
trust me I've been there, done that for 45+ years now

gears, & the 8-3/4" for a manual trans for a street/strip combo car
it's always a compromise, weak, but can be made way better...
I always sided on more gear, a steeper gear, bigger #s, than a 3.55:1
(unless you make a hug HP/TQ #s to pull them higher gears, still a compromise)
3.90:1 min. gear, more so a 4.10:1, or taller tires & 4.30 or 4.56:1
or steeper with bigger/taller tires, IMO win, win it's more rubber to the ground
moves a heavy car way easier, torque multiplications of steeper gears,
& a bigger footprint

IMHFO the 340 is weak link in the (your) equation, no offence
you don't even know what it has in it, you need to know that stuff
everything else is dreaming stuff
I know what it was like to be a teen & want a fast car I always had one
it's expensive & you sacrifice a lot of other stuff to get it
you are handicapped already, small engine (340 in a 3700+# car with 400# of torque),
not much torque, in a big heavy car
again no offence meant, just facts truth realistic stuff
to want to go fast in a heavy 71 B-Body car,
or screw up a #s matching deal
but you can work with it
& if you don't care about not spinning a bunch of RPM, like 3,500 (+) at 55 on the hi-way
get a 4.10:1 rear gear a 28" tall or taller (more roll out, & wider the better)
you sort of want like a 10:1 in your 1st gear ratio for drag racing at a min,
1st gear ratio X the rear gear;
example 1st gear 2.45:1 x rear gear 4.10:1 = 10.05:1
example 2.45:1 x 3.55:1 = 8.69:1 yours not cutting it for a non boosted heavy car
unless it's boosted or N2O a completely different animal than a NA engine

Need stiff sidewall Bias-slick
or same in a Drag Radial, needs to be a stiff sidewall for an manual trans
stiffer sidewalls takes a big shot/hit better

you could get a GearVenders over/underdrive, they ain't cheap either
that's in the dreaming realm probably, but will solve the street strip element

all about power to weight ratios, less weight takes less to move it
some aluminum parts where you have steel, brass or cast iron helps too
or fiberglass bumpers/aluminum bumper brackets
& fiberglass hood, will help some but sacrifice looks, if not done right
not exactly cheap for good fiberglass nowadays either
weight off the front to get weight transfer, your car obviously needs badly

**edited added; forgot to mention it
Free, just a bit of time
disconnect the front sway-bar links at the track too,
zip tie up the bar or take it off save a few #s too, at the track
but it helps on the street for handling
But at the track, without it, will help to lift the front more, weight to transfer to the rear**

maybe a trunk mount battery, I know all the naysayers
downfalls, you will need to have a remote shut off switch, to run at the track
but a great way to get a bunch of weight off the front/nose
& add to the rear (right rear)
double what you took off the front on the rear wheels

do something about traction aid, you'll need it
good adjustable (or dbl adjt.) QA1 or Rancho shocks are relatively "cheap"
in/for what you get
they will help a bunch, especially on a stick car
you will still need stiff sidewall Bias Ply slicks or Drag Radials too

Calvert CalTracs work on leaf spring cars,
easy bolt on stuff & they work, been proven run in S/S or Stock Eliminator
I had one going, street driven a lot drove to the track & cruised a lot too
best of 8.58@156 w/a 1968 383/479cid low-deck w-A727 4,200rpm vert,
in a 68 RR RM23 HT on M/T 315/55/15 Drag Radials, drove all over Sacramento
sold it to a guy still in Sac., be aware of a sliver 68 RR w/black 6bbl lift off hood,
Halibrand kidney slots, a lil' lower than stock, he'll blow your doors off
(383 block, lots of $$$ making it work, I know what it takes, been doing this **** since 1977,
going 8's or faster, since I was 17 & it's not for a novice, I had a lot of great advice, my elders)

A 4 link;
no matter which is a bunch of fab work, any of them requires some welding
& 4 link really isn't for a novice either
some like the QA1 or Ride-Tech stuff, are triangulated 4 link
are a bit easier tuning setting up, still aren't bolt in need welding, a experienced welder
a real 4 link race set up is not for a novice, lots of research needed, planning etc.
& right shocks are critical, in either equations

A 383 block albeit you can find them cheap, there's lots of used up junk out there
they made millions
BUT it is the weakest of the Big Blocks,
a 400 low deck block is way better (even better than a 440 block),
have a bigger bore too, more cubic inches, in the same real-estate/engine space
They have thicker webbing on the mains,
if you want 700hp, the webbing in a 383 block, won't last long before it cracks
or you get main-cap walk, even with a girdle & studs (I know)

But; a cavate
you can very easily get 500+hp out of a good combo'd 383 'easily'
you still will need the same deal
*a good set of heads flowing 300cfm at a min. at 0.600 gross valve lift
*a good matched cam, springs, retainers & valves, adjt. rockers etc.
(not stock ****/stamped steel)
*a good compression ratio, forged piston, at or near zero deck, w/good quench
piston at the top of the deck, with proper valve relieve to have good valve to piston clearance
for your specific camshaft, IMO a min. 0.540" gross valve-lift,
you can get there with an adjustable 1.6:1 rocker (rollers) if needed
*a good induction/intake & carb (I prefer Holley style carbs over any Carter or Edelbrock)
street/strip, street driven a lot a Edelbrock Performer RPM is a great manifold, dual plane
with a 1" spacer/tapered 4 port or open
a single plane can work too, a 1" 4 port tapered spacer will help drivability/street manners
*a good ignition, to burn the excess fuel you will need to make HP
*the right gears for the camshaft & complete engine trans combo
*headers (long tube, you said you have) but an 1-7/8" min. if the room is there 2"
'or' at least at the size or bigger of the exhaust valve diameter

you can get that more easily with a 440, it's 4.320" bore x 3.75" stroke
more cubes/more torque
but not the best block IMHFO

**or in a 400 low-deck (smog era) block will live longer,
unless you have an expensive aftermarket RB block
because of the webbing strength or thickness in the 400 blocks,
is considerably stronger & thicker
common put a 440 crank with smaller mains diam. of a low-deck 383/400 block
a lil' bigger bore to start with too
400 is 4.340" bore stock x 3.375" stroke, stroke same as the 383
& 0.030"/4.370 over & a 3.75" (440 stroke) crank is like 449cid
or (most I'd dare go bore wise) 0.060" over 4.400" x 3.75" stroke is like 456cid
(buy one made for it, the radius of the counterweights have to be turned down to 7.125" too
expensive to do all the necessary machine work, member @PROSTOCKTOM
sells/has some great priced & good parts/stroker kits)

there's a lot more to a combo, than just a manual trans & an engine combo
you can make a crapload of power & never get a good time
if the whole combo isn't set up correctly, the car too

you're young, "I assume" study &/or read about it
lots of great books, you can use & look at repeatedly for reference sake
MoPar Performance is just one good source for chassis or suspension or engines/combos

OK I'm done for now, lecture perf. 101 is over
a lot of good advice from a lot of respected members here
listen & you will learn from most of them

 

[dvw]

Just an idea. You could put in a torque strap that is just barely loose. That way the rubber won't stretch enough to break. If you put in solid mounts and drive it on the street it will rattle your teeth

Have you ever driven solid mounts? I would bet not. There isn't much of a difference.
Doug

 

[340runner]

Have you ever driven solid mounts? I would bet not. There isn't much of a difference.
Doug

Yeah, I didn't drive as I don't want to in the cold, but I've started it and sat till it was warmed for a bit at operating temp because that's how I keep it up for winter maintenance

At idle it wasn't bad at all, no rattling my teeth or feeling vibrations in my *** for the next 24hrs
Little more vibrations at the steering wheel than I remember, but that also might just be me being used to a modern vehicle with all the comforts. Still not terrible at all

Don't think it'll be that much worse at all when driving, but we shall see