Moparkrazed
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Ok cool. That was my fear going with too tall of a gear and going north of 3k rpm at 70.
Rear end gear with 727?
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my 66 has a 440cu + tko 5-speed + 2.94 gear + 26” tall bf Goodrich tire
80mph is about 2000rpm for it in 5th
then there is a big difference in speed when it gets up to 2200rpm
watermelon
80mph is about 2000rpm for it in 5th
then there is a big difference in speed when it gets up to 2200rpm
watermelon
Gus chiggins
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Yes, i was thinking about tire size, gear, i figured the torque converter is part of the equation, no?
Not really if you're using fairly normal converter. Some of the factory ones were higher than a guy would think.
It is a big part of the equation, so is camshaft selection because you’re going to be disappointed in the performance if any part of the combination is mismatched.
The old Direct Connection catalogs listed recommended combinations for various performance levels. I consider them to be good guidelines for a novice builder, as long as you have realistic expectations. For a comfortable highway cruiser you’re going to want a fairly conservative combo.
Thrashingcows
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If you want a car with good driving characteristics in and around town, and good hwy cruising I'd stick with a mostly stock torque converter, maybe run one rated for the larger C-bodies and you should be pretty happy with things I'd think.
I've run 2.76. 3.55, 4.30 in my 360 powered Challenger (12.70s with the 3.55). It has a 2.47 low gear 4 speed so the 2.76 was sluggish in 1st gear. Drove fine though. 275/60-15 tires . It all depends on where you drive. Mostly 60mph + roads? In town seldom to 60mph? I've driven with 4.30s Detroit to Columbus. It all depends on how often. Then ask yourself how quick do you want to accelerate? Want brutal? 4.10 or more.
Doug
Doug
Moparkrazed
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Thanks watermelon. I was considering tko 5 speed as I wouldn’t have to cut the floor and I like having that extra gear. The car is currently a column shift so I’d have to buy a lot to convert it. But still thinking hard on that 5 speed. How bad is it on acceleration from a stop light?my 66 has a 440cu + tko 5-speed + 2.94 gear + 26” tall bf Goodrich tire
80mph is about 2000rpm for it in 5th
then there is a big difference in speed when it gets up to 2200rpm
watermelon
Moparkrazed
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Thanks Doug. I live in what used to be country but everyone and their momma is moving in town haha. I’ll use it for some in town driving but really want to get out on the highway and keep up with traffic. Definitely don’t want 4.10, the acceleration would be fun but highway driving would drive me crazy.
SlinktRR
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If you go with tko-600 the final drive in 5th is 0.68 (overdrive). With 4.10 gears and 28" rear tires you would be 2500 rpm at 75mph. If feeling conservative you could use 3.73 or 3.55 to loaf along at 2000rpm like a modern 6 speed car. I have thought about that conversion many times! Best of both worlds.
Moparkrazed
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Thanks slink definitely thinking about that hard. All of this calculating stuff is way over my head but I’ve never really jumped into it. Thanks for breaking that info down for me.
SlinktRR
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from a stop it moves out quick
it’s not a drag setup but this particular combo gets nice long pulls in each gear
or if needed it can burn rubber
1966 Coronet...tire test
440 to TKO500 … burnout
watermelon
it’s not a drag setup but this particular combo gets nice long pulls in each gear
or if needed it can burn rubber
1966 Coronet...tire test
440 to TKO500 … burnout
watermelon
Moparkrazed
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Thanks for sending that Slinktrr
Moparkrazed
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Nice. That sounds like what I’m looking for. Thanks for posting those watermelon.
Thanks, that's fun to play with. With my 3.23 and my 27" tall tire, I need to stay under 50 mph to stay around that magic 2000 rpm engine speed for better mileage. I need a overdrive. Too bad you have to modify to put one in.
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This depends on several things....The money that you're willing to spend and what kind of daily driver that you're used to driving.
Higher performance engines make their power at a higher rpm, so a "stall converter" slips more at low engine speeds. This allows the engine to more easily rev past the low rpms and get into the power range without the converter fully engaging. Think of it like when you rev up a manual transmission car before releasing the clutch. A low stall converter would be like releasing the clutch at 1500 rpms. A higher stall is like releasing it at 3000 rpms.
Overdrive, whether in an automatic or a manual transmission is THE way to go when you want to have flexibility in a street driven car.
A torquey Big Block will do fine with a 2.76 or 2.94 axle gear once it is moving but it will not feel as snappy from a stoplight as it would with a 3.23 or 3.55. Sadly, this is an area full of compromises.
The TKO series has been replaced by the TKX. Even the TKO requires some floorpan modifications but nothing structural. The TKX is slightly smaller but you're still looking at cutting a hole for the shifter. These Tremec trasnsmissions have shifters that must pass through the floor just like any other manual transmission. Stock 4 speed models had the shifter and linkage on the side. The Tremecs require a hole on the top of the transmission tunnel. It is not difficult to do.
Actually, the TKO had two overdrive ratios available, .64 and .82. I have the .64 ratio. It is excellent. The TKX supposedly only has the .64 ratio.
What you'll find with the 5 speed is that no matter the condition, you always have the right gear to use. Mine has the 2.87 first gear ratio. This is deeper than any regular Mopar 4 speed so it gets the car moving a bit better. The .64 overdrive means that at freeway speeds, the engine will now rev 36% slower than a 727 or a regular 4 speed. Freeway speeds of 3000 rpms will rattle your brain after awhile. Most if not all of us have become accustomed to lower rpm freeway operation with our later model cars. The interior noise is reduced, the engine noise is reduced, the car gets better mileage and the road trips are much more comfortable. The Tremec 5 speed swap was one of the best things that I did to my car. I went from maybe 10-11 mpg to 15 in my 440/493 Charger with a 3.55 axle gear.
While that may not seem extreme, any increase in mileage means an extension of time and miles between fill-ups at gas stations. If you've ever worried about making it to the next station, longer range really eases your nerves.
This thread is long but it covers a LOT:
Tremec 5 speed conversion in a 1970 Charger
The 6.4 HEMI is a great engine but will cost you about double to swap in compared to a 440 when you factor in the fuel system, electronics, special mounts and exhaust system. The parts to do a 440 swap are easier to find and a lot cheaper. A stock 6.4 will make about the same as a mild 440 but get better mileage. The decision as to which engine to go with is up to you. Both have pros and cons.
Good luck!
If cruising comfortably at 80 for long distances is parg of the plan, some sort of OD is the only solution "in my opinion".
Any rear gear capable of that with a 727 will be a turd off the lights, regardless of how much torque you make (you still have to hook that power up).
It all depends on what you want. Some like the 3.23 but for me, that kills the acceleration 'fun factor' way too much.
Something else that gets lost in the conversation is how squirrely these old dogs can be at 80+ on the freeway without some steering/suspension/brake mods, so don't neglect that stuff if your goal is high-speed cruising.
Any rear gear capable of that with a 727 will be a turd off the lights, regardless of how much torque you make (you still have to hook that power up).
It all depends on what you want. Some like the 3.23 but for me, that kills the acceleration 'fun factor' way too much.
Something else that gets lost in the conversation is how squirrely these old dogs can be at 80+ on the freeway without some steering/suspension/brake mods, so don't neglect that stuff if your goal is high-speed cruising.
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I laughed a little here.
It has been my goal to make my cars handle great instead of go real fast in a straight line. I forget that more Mopar guys are drag racers than road racers.
I agree with the bean dude… to cruise safely and comfortably at 80+, you do need better tires and a good modern alignment at least.
Mine tracks straight and true with the stock based setup and lots of caster.
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