I can't decide if I want to go with a new generation style iron block or a LSX six bolt block for boost. I'm wanting run 20-25psi via a GT91 turbo. The 4 bolt block is definitely the cheaper route.

 

Pick your poison, I know people running that kind of boost on a 4 bolt block just fine. The cylinder walls in the lsx aren't any longer than a regular iron block so you're still going to have a lot of piston rock with a stroker crank at BDC. I like sleeved blocks or aluminum blocks for stroker applications because they've got a longer cylinder skirt to keep better piston stability at BDC and minimize egg shaping of the cylinder walls. All depends on what your realistic mileage expectation out of the motor is too.

Personally if you aren't trying to break records I'd stick to a 4 bolt block simple because if something happens I'd rather blow a hradgasket than a piston. On a 4 bolt block you're going to have to be even more careful with your tune to make the headgaskets live with that kind of power.

 

Id prob go with a factory late model alum 6.0, or L92 block and trick flow or afr head. This will likely be my rout if I decide to build a hot combo.

 

I've had on few sponsors that have contacted me on this. I've looked into buying a long block from Texas Speed, very reasonably priced. That would be a new generation iron block 408 with PRC LS7 cylinders heads. Runs about 8500 for the long block shipped. All the other estimates for the same engine have topped 10.5K and up. A LSX long block will be closer to 15K. I thought if built correctly the skirt wear was not a problem. Is this still an issue?

 

There are a lot of things you can do to lessen the effect with wider skirted pistons and rounded cylinder bottoms but at the end of the day IMO its not a good idea for something you expect to get a lot of miles out of.

 

So how can you get around this?

 

A custom 4032 piston would be my approach. Are those Ls7 heads going to hold the boost?

 

you check out the aes 390 and 410?