i am doing a twin turbo set up on my 87 iroc. I was going to use the block frome a 88 chevy truck with a splayed 4 bolt billet cap swap. I was told that the 85-86 blocks are thiner than the older blocks and will not take the power as well as some thing from the 70's any one hear of this. the combo i was going to run is

383 with eagle forged bottom end
stock block from a 88 chevy truck with splayed 4 bolt billet caps
afr 210 heads race ready porting
dont know about the intake yet
and a csu carb
the headers will be built by me
and ill be running some sort of air to air intercooller
the turbos are 2 to4e
57 compressor wheel trim
0.50 A/R compressor
0.82 A/R hot

 

I've never heard of the newer blocks being cast thinner than the old ones.

If you have a forged bottom end and splayed 4-bolt steel caps, I'd say that would be pretty tough bottom end.

 

i think if it were me i'd trash the block and get a dart or bow tie block. as for block thickness if you're worried about it have it checked and you'll know for sure.

 

later blocks do have thinner cyl walls,but with only a .030 over bore it should be fine,but i would have it sonic checked just to make sure.if ur gonna only run 5-7 psi i wouldnt even worry about it.could always hit the junkyard and try to find a 0010 block

 

the block is 30 over and it is going to see about 8 on the street 12-14 on the track I was told by the gm guys at turbo mustangs that it would only take about 500 safely. what would be a good thickness to use as a min on the walls.

 

i'd ask your engine machinist what he thinks is a good amount of wall thickness to have left, while he's sonic checking it.
I don't think you'll crack the block, the walls take much less stress than the pistons and heads do, the cylindrical part of a cylinder takes 1/2 the stress that the top/bottoms take, IIRC.
That truck block setup for a roller cam? you using a roller cam?

How's your fab skills as far as the turbo tubing goes? I hear it's pretty tricky...

in case you overlooked it, make sure your 383 kit is for the 1pc RMS block (assuming you have a 1pc RMS block)...

 

my fab skills are good. I have been welding for about 10 years. the block is a non roller block but i am going to run a set of roller conversion lifters in it. and ya i know about the one peace rear main but gm dose make the adapter if you can not get the exact crank you want in one piece.