Do the aluminum blocks have lower cylinder walls?

One advantage is fuel savings for a DD if driven moderately. I know a blown 383 will still be a hog but would still be better than a 408. Kind of like a blown 5.3 vs a N/A 6.0. The power is still there if you want it but the smaller displacement means better economy for lighter DD'ing. Now I realize that if we're strictly talking performance, the 408 is king... especially with FI.

 

I believe you will have a good running combination at that size with your current blower. I personally would still prefer to run a 0.030” over 6.0L block with either a 3.750” stroke (still a 383” with larger bore) or a 3.875” stroke for a 395”. At the far end, maybe a 3.900” stroke to end up with a 398”. Any one of these will keep the pistons a little further up in the cylinders, but while the cranks and corresponding components are available, it’s hard to beat the prices of all the 4.00” stroke kits that are on the market, they just sell entirely too many and the prices reflect it. Besides keeping the pistons a little higher up in the bores, it also gives you a little more leeway with the heads and valve sizes, not to mention ring packaging. That doesn’t mean to suggest that I believe you shouldn’t go ahead and build the motor as you’re planning, especially if you already have the 5.3L block, and there is nothing wrong with being different, but 1slow01Z71 is right.

 

Yes aluminum blocks have longer cylinder skirts keeping the piston more stable at BDC. When/if I ever build another stroker it will be out of an LS2 or LS3 block.

 

At 5800 lb's,its gonna take over 1000hp at the crank to push the truck into the high 10's if everything else is perfect.

Id say 427 or 454.

 

Well, since I have the pistons but not a block I'll hold out for an LS1 or LS6 block. I already looked into an L33 block but it looks like the sleeves are too thin for the 3.905 bore.

BTW, is there a 3.75" crank readily available?

 

I'm glad you guys brought up the longevity point, because I would like this engine to last for a while as well. If a 370 can help me reach my goals more reliably than a 408, then that would be the way to go.

 

Damn you, I was about to mentio the point you just did. Sure the 408 will give more TQ but you hinted that it's gonna all come out to the same hp. (your quote on big cubes low boost vs. smaller cubes and higher boost) led me to believe you have a hp goal in mind. that being said, both those engines will reach it, more or less the same so might as well stick with the 370 which like cody said will have less piston rock/slap.

 

I don't really have a power goal in mind. Performance at the track is a good enough indicator for me, so whatever will carry me to a 10.90 is good, regardless if it comes from a larger or smaller motor. I am definitely leaning towards the 370, though. It's a hell of a lot cheaper than the 408 too I'm an easy victim of persuasion though, so by all means, throw in your opinions/ideas!

 

I say 370. You're gonna need alot of boost and a well planned longblock to get into the 10's. I don't think that the 408 will give that much more to you than the 370 could.

 

you can also have a 382 from a ls1, however for the cost of building a 382 youll have same money into a 408. since pistons cost the same no matter what size motor [unless a custom] cranks are both 4" so same cost and rods are the same. for that its almost easier to go 408

now to the OP i would use a 408, the hp will be the same but torque is made from cubes. you can make 800 hp from a 4.8 but torque lacks and the heavier the vehicle the more torque you need.

as for longivity that comes into question. i have yet to see someone in the performance world keep a project long enough to be aconcern. most sell them, most redesign the build before it becomes a issue.

this comes to the mix as well. ppl dont realize how much it actually costs and the requirements of a build like this. Once a build gets to a certain point, its time to make it a toy and not a daily. Im not sure your financial situation but the cost of a 1k hp build is beyond most ppl's toy fund but ppl do achieve it. now ask yourself can you afford to spend that money twice or maybe 3 times? the maintenance of say a 20k build over the years vs the cost of building that 20k build and using it as a toy. turbos wear out, blowers wear out, hp trannys wear out, and etc. somethign to think about, after spending 10s of thousands of dollars on my truck no way in hell i would truely daily that much cash. its not worth the wear and tear to replace the parts over and over again. a 1000hp truck leads to a purchase of another truck/car.........something to think about........... leave it alone and enjoy it or plan to spend more money then you wanted and then hate your truck