340 vs 400 vs G3Hemi

[74SRT]

1974 Plymouth Roadrunner "Clone", original 318/904.

Im turning my car into a Mean street car so reliablilty/driveablity, and hp/tq are important. My goal would be to make the car run high 11s at the track possibly low 12s.
Overdrive 5 or 6spd trans and a Strange S60 3.** rear with true trac. I will also be doing EFI.. I originally wanted a 400 stoker with ~650hp/tq. But.. I've been seeing some Nasty small blocks and wicked new hemis puttin some nice numbers out. A new hemi seems like too much work and $$ for not enough power. A 340build will be more expensive than a 400 stroker, But it will drop in with no clearance issues or $1200 motor mount kits.. I want to do the 400 but they are heavier which affects handling and idk how many issues its gonna give me with clearance i.e. headers, starter,etc... comments or advice???

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And by the way, this car when complete will be driven Regularly and must run on pump gas!

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Also if anyone in here has done or knows a rough estimate on a new hemi swap price tag that would also be helpful. Although im pretty sure this decision is leaning more towards 340vs 400

 

[HawkRod]

How about stroking the 340? For example, Scat makes one for 416 CI

http://www.rpmmachine.com/340-416-chrysler-stroker.shtml

Then you get lighter weight, no motor mount issues AND more cubic inches...

 

[74SRT]

Good point sir! But. My only problem with a small block vs big block is that a big block will Devour a SB with Torque. Which in a heavy car like mine is definatly needed. For the cost of a 416" 340 I could biild a 470" 400 that would Easily make well over 500ft lbs. And its cheaper! But as I said, will it fit good? Im kinda waitong on that answer. I do love the 340 but I would rather have one in an A or E body. My car is heavy.

 

[Greg Ducato]

My Hughes built 416 made 578HP and 580Lbs of torque in my 1970 Challenger which is not as light a car as you might imagine. It was insanely quick for a street car, probably the quickest street car I have owned. With the right gearing and some traction you could easily go mid 11's in your B body

 

[RustyRatRod]

I think the new Hemi would be awesome cool if you have the budget. I usually don't agree with the modern route, but how many big or small block cars have you seen? A boatload. I know people are doin new Hemi swaps, but there's not a lot of them out there yet. I think it would be cool.

 

[74SRT]

My Hughes built 416 made 578HP and 580Lbs of torque in my 1970 Challenger which is not as light a car as you might imagine. It was insanely quick for a street car, probably the quickest street car I have owned. With the right gearing and some traction you could easily go mid 11's in your B body

Dang! Thats some nice power! How reliable are the sb stokers?

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I think the new Hemi would be awesome cool if you have the budget. I usually don't agree with the modern route, but how many big or small block cars have you seen? A boatload. I know people are doin new Hemi swaps, but there's not a lot of them out there yet. I think it would be cool.

I agree Rusty, BUT. Thats a lot of fab and $$ so I think im gonna stick with a mostly bolt in app. Considering im already doin a trans swap, that alone can be a nightmare especially with the T-56 6speed. But again I do agree, it would be cool to have a 6.1 in a 74 B. I dont think I've seen Any of those done yet.

 

[Supershafts]

motor Mounts.... Use elephant ears...forget mounts.

Now you can put what you want and NOTHING to worry about routing headers around mounts and set the motor level no unwanted angle.

The fixed hemi can make power, the sb can make power, and the big block can make power...

The fixed hemi can do it with the heads it has, everything else can add up

The stroked sb needs heads, not that dopey mag style head either, preferably BIG heads with the stroker and you can get 600+.

The stroked B needs heads, yeah it could do decent with the right factory head, i have a modified 6pk motor puts the 73 RR into the 11's, pump gas.

However, a B or RB stroked motor done with the right parts and using indy heads will easily make 700hp and have more options, a large roller in a big stroker keeping the RR in 1.5 /1.6 area is nice and streetable, then when you do the bottom end have them do it for additional duty and then you can have 700 hp constant and have another 200 hp on a nice nx plate.

 

[dsd1967]

The big block should fit with no problem....they ran big blocks in that body style through those years. I think the K member changed from small to big block, but you could probably pick up a BB K member for around $100-$150, or go with a Shumaker conversion for around $170 including shipping and handling.

Since you are putting a different transmission in anyway...you will have to find a new bellhousing, so that's a wash either way. I would say to go for the BB cubic inches. Especially if you want reliability.

 

[69clone]

I was in the same boat as you when I was trying to decide what to do to my 318 69' satellite. I thought about going with a stroked 360,440 or a new hemi... Finally decided to go with a big block have a 440/498ci waiting to go in when it warms up. Pump gas engine built for the street and yet it still made 626hp/640ft tq.

 

[67 coronet]

the big block will give you the most bang for the buck,as well as the best drivability for big power.only time you need to worry about big block weight is if you plan on doing some autocross.it will only be a minor diff for street use.

 

[74SRT]

Good points.
I think I'll stick to my guns and go with the 400.
What strokers make good reliable power? If I do go this route I will Definitely get aluminum heads.
Im going for an all around performer. Handling has to be there too. I want one of those Magnumforce tubular K's but 6k on front suspension is a bit more than I wanna pay.
And some of you may laugh but I want to get decent mileage hence EFI and overdrive trans. So 500rwhp and 10-18mpg shouldnt be a big issue right?

 

[kb67mopar]

I might be a bit biased but in a recent issue of Mopar Muscle they built a pump gas 426 stroker late model hemi with 6.4 ported heads from Indy that made over 750 hp and over 1000 with a turbo.

The late model platform lends itself extremely well to your idea of running fuel injection, pump gas, and light weight. A stock 6.1 already runs 425 hp and the parts are not that crazy. Start with a 5.7 block (I have seen them for $400 recently) buy a stroker crank and start putting together your combo and I bet you can be over 500 hp pretty quick with less investment then that of a big block.

If you already plan to retro-fit a different trans in then the rest is cake ....

 

[74SRT]

I might be a bit biased but in a recent issue of Mopar Muscle they built a pump gas 426 stroker late model hemi with 6.4 ported heads from Indy that made over 750 hp and over 1000 with a turbo.

The late model platform lends itself extremely well to your idea of running fuel injection, pump gas, and light weight. A stock 6.1 already runs 425 hp and the parts are not that crazy. Start with a 5.7 block (I have seen them for $400 recently) buy a stroker crank and start putting together your combo and I bet you can be over 500 hp pretty quick with less investment then that of a big block.

If you already plan to retro-fit a different trans in then the rest is cake ....

No denying that, those motors do make awesome power. But the time and fabrication it takes to get one of tjese in and running properly cost more than the motor itself at times. Thats my problem with this motor. I do have a 5.7 block in storage, got it for free!

 

[67 coronet]

i still dont think there is enough available for the 3rd gen convertions as of yet.you have to do alot of fab work to use them in our cars.plus the electrical can be a bitch.the 500 and 512 inch kits from 440 source look impressive but i have not used them myself.you can make 1 hp per cube very easy with that set up.(or go crazy like me and shoot for 750 hp,but there goes your millage window!)

 

[dsd1967]

If you are going with a 400 block, I wouldn't be too worried on the weight difference either. I found a chart that listed engine weights

340 = 525#
400 = 620#
440 = 670#

If you do a 400 stroker with aluminum heads, intake, water pump housing and water pump, you will be darn close to the factory 340 weight. Add in an aluminum radiator, and you may meet or beat the weight. Granted you could do the same with a small block and get better weight savings, but at least you can get a big block close to the factory weight of a small block....therefore the handling characteristics should be similar.

 

[Hemi Rebel]

There is anything you want for the 3g hemi. From bone stock to stroked and poked with a huffer on top. Or turbos. Pushing over 1000hp. And thats totally streetable too. And probably better mileage than a 600hp stroked 400.Yeah, its a bit pricey, but everything can be had to drop one right in. The bellhousing is small block so you can use a 727 or 904 if you want. In this day and age its just a matter of what you prefer and what you want to pay. All three motors you want to choose from are good motors

 

[RustyRatRod]

All three motors you want to choose from are good motors

Did Chrysler make a bad one? The 2.6 maybe?

 

[Hemi Rebel]

Did Chrysler make a bad one? The 2.6 maybe?

Yeah, luckily they were pretty much done by the time I started working on cars. The only one I remember came in with a 2 piece cam. So that was the end of that. The early neon motors and the 2.7 v6 can be added to the list too

 

[74SRT]

Yeah, luckily they were pretty much done by the time I started working on cars. The only one I remember came in with a 2 piece cam. So that was the end of that. The early neon motors and the 2.7 v6 can be added to the list too

Lol. Most of those 2liter motors were Mitsu's though. I can say chrysler didnt make a transmission worth a dam during the 80s/90s and truthfully still dont. Nor did they ever make any real "efficient" v8's. (R/T 5.9s) but.. we still have the best looking cars around and the old schools are unmatched in my opinion.

 

[5.7 hemi]

Gee, a 5.7/6.1/6.4 is a bolt in with TTI mounts, so what hacking/fabbin' are we talking about?