High HP Gen III Hemi? How strong are the blocks?

Thinking about the motor for my next project. 3400lb duster, cage will cert to 8.50. Looking to run sub 9's on 275's and leaf springs.

Thinking about doing a new hemi (heads are VERY good), just don't know how good the blocks are?

Figure it'll take ~1000hp at the tire do get there?

Anyone have or know of one? How good are these things? Is a 5.7L block better/worse then a 6.1L or 6.4L?

My buddy did the 5.7 base and stroked it to 426, he did a 3/4 fill on the block and IIRC he used the new 6.4 heads, he also went with a pro charger and has been 7.60 in a Demon. I have heard the the 6.1s are thin as far as the block goes, but everything I have heard about the 6.4 has been good. The problem with that is they are not as easy to score as the 5.7. That is what I'm doing also. In one of the cars just haven't decided which one yet. I would send a PM to steff or 340 rick, both are doing neat stuff with gen IIIs. There is someone else I just can't remeber his name...

AlexP is the other. He has lots of go info also...

STEFF would be the other one. He is using a 6.4 block.
As for availability of the 6.4, complete Short block RL086564AB are as low as 2200.00.

Man I got to lean to read better

Is the 6.4L a lot stronger then the 5.7L stuff? The 5.7L stuff is a lot cheaper.

I can buy a whole running 5.7L for the price of that 6.4L shortblock.

But if they won't hold the power, then I suppose that doesn't matter.

From what I have heard, they are about the same. I'm using the 5.7 base just cause I have one. If I didn't I would go 6.4 route. Thing is to have the kinda HP your looking at I would still 3/4 fill the block either way you go. Oh and yes you can still drive it on the street, my buddy drives his all over the place. Its a blast to goto the track with him blast off a 7.60 and drive out the Gate.
The problem is your going to have to replace the crank, rods,pistons, ect. So why not just go 5.7.. I found mine 30 miles away, that was knocking for $500.00 .. So there are deals out there just gota look..

That is sort of what I'm hearing too. I wonder if the forged 6.1L crank is strong enough for big power?

The 5.7 block is stronger than the 6.1 according to our sonic check records of many blocks. The 6.4 block is way stronger than both.

As far as the factory crank? I use a factory 6.1 crankshaft and had offset ground it from the 3.58" stroke to 3.795" stroke in my blown Gen III 6.1 block 392 Hemi truck. This was also back in 05 when no aftermarket parts were available. My 05 4x4 Ram truck weighs 5184 lbs, cuts high 1.40 60's, high 6.80's @ 98 in the 1/8 and a best of 11.03 @ 118 in the 1/4. (1/4 mi cross sectional denity at its best lol) I had to freshened up the engine after a burnt exhaust valve with 400 recorded passes later...Mag'd the crank and Eagle rods and both checked out fine and are back in the motor.

I would go the 5.7 route, just for the ease of finding one. The HP level you are shooting for any of the 3G's would be fine at .030 overbore and short fill main studs etc.... but 6.1s and 6.4's are more expensive and harder to locate.

When building a boosted engine the diff between a 392" motor and a 426" would not be worth the extra money for 30 cubes.

Good luck

I really like the 5.7's....they don't check out as well as some of the other blocks, but if Jerry hasn't broken one yet...Nobody will!

I would have no issue putting 1100-1200rwhp to a partially filled 5.7 that had good walls on it.

My personal favorite motor of all of the Hemi's I've had my hand in was a .005 over 5.7 with a Callies 392 kit (4032 pistons), a 235/247 camshaft, max ported 5.7 heads (heavily worked) and a ported 6.1 intake.

490rwhp on the second revision of the tune through a 3500 stall. I think it had another 20-30 horse in it with more tuning and the tables available in today's Diablosport menus.

Ran 11.53 @ 117 with less cam 223/231, a plastic 5.7 car intake and a mild head...that was 450rwhp...

He swapped to a roots blown 6.1 426 and regretted it every day after....it broke more drivetrain parts than he could afford.

I'm only running a 6.1 block because I wanted a 6.1 block...no reason else.

Im thinking it would probably be easier to package a twin turbo Gen III in my Dart with acc,A/C,Power steering etc. than one with say some TTI's and no turboes. Is it possible to flip exhaust manifolds side to side on these or no?

Is it true that one of these hemis are actually wider overall than a RB?

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Im thinking it would probably be easier to package a twin turbo Gen III in my Dart with acc,A/C,Power steering etc. than one with say some TTI's and no turboes. Is it possible to flip exhaust manifolds side to side on these or no?

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I can agree with that. You can't flip them side to side though. My friend fabricated his own headers from a set of JBA headers to fit his A-body with PS and AC.