Machine shop says that main studs is a must on a boosted LS, this is a SBE Gen IV that will see 10 lbs on the street and 20 or so on the strip. It'll have a forged rotating assy later. I've seen a lot of people making big HP with out studs but I thought I'd ask. If not studs, do you recommend new main bolts?

 

Find a new machinist. Not being a smart *** either.

 

If you're digging into the bottom end anyways, studding it isn't a bad idea. Is it "needed" no, but in my opinion if you're already in there, might as well do it. I did ARP studs on my engine.

 

If its at the machine shop, and in your budget, why not, have line bore checked though. Will stock bolts work, prob, but sometimes that future rotating assemb. doesn't happen, so you have a little extra protection. If you just swap in new stock bolts, only use GM's.

 

If your future plans are to make big power under boost 30-40 psi then I'd have the block machined for billet main caps with ARP main studs and 1/2" head studs. I'd also machine the heads and block for o-rings and I probably wouldn't be doing this to an GM aluminum LS block either I'd be looking at iron blocks and if my pockets allowed the DART or LSX iron blocks.

 

this.

OP. Cheaper to do it once right the 1st time.

 

This ^

 

If you built it with stock bolts and it had a problem such that you had to rebuild it again, would you use studs the second time?

 

I dunno, if I have the engine out and being built, I'd do studs just for piece of mind.
You're gonna ask a lot of that block and rotating assembly in short order.
It doesn't take long before 500whp turns into 600whp, then into 700whp and so on lol.....

 

 

I build a couple motors per week. If you’re using stock crank, use stock bolts. 4340 crank gets studs.