BigBirdTA

I am putting together a 408 iron block LQ9 motor. I'm using Torque-To-Yield GM LS2 headbolts which are shorter that LS1 bolts. The question is, given that they're going into an iron block instead of aluminum, should they be torqued down to a different spec than the torque spec for stock because of the different material?

And what about the outer bolts that normally on LS1's are torqued down to a lesser ft/lbs that the rest of the longer ones? Torque all the same, or torque as per GM spec for aluminum block?

kickassT/A

iTrader: (3)

you can only use the ls2 bolts if its an ls2 style iron block. the later iron blocks require ls2 head bolts, but if your block isn't one of these then you need ls1 bolts. the torque proceedure will be the same as it it on the aluminum block.... just a question, but if you dropped the cash on a 408 why are you cheaping out on head studs?

BigBirdTA

Don't plan on running nitrous or boost. Nor is it a race car so don't plan on taking the heads off often. The GM bolts are fine, thousands of cars leave the factory with GM bolts and never have a problem. Done a few H/C swaps already on LS1's and never had a problem with the GM bolts.

The 408 is the later style block and uses the shorter ones. Earlier, I called TSP and they said the same thing, so looks like I'll just torque them down per GM specs.

Thanks for the info.