i got my lt1 383 built at a local speed shop and they told me to retorque the head bolts after i turn it on for about ten minutes for the first time. i have felpro head gaskets and arp head bolts. do i have retorque them or will i be fine if i dont? why would i have to retorque them?

 

Expansion and shrinkage of various parts due to heat and cold would be my guess...

 

It's going to be a royal pain to get to all the bolts to do it. AFAIK, the Fel-Pro perma-torque gaskets are specifically designed to not need retorquing. They have been around for many years.

As a side note, I did not find anything in the popular LT1 rebuilding book by Mike Mavrigian that says anything about retorquing the heads (unless I missed it). Another thing is, that if the torque-angle method was used to tighten the bolts, they would all have to be relaxed and then totally redone. That doesn't sound like a good idea to me.

 

ARP recommends retorquing all the head bolts after the first heat cycle. But I didn't do it.

 

What do you guys usually do - 45, 55, 65-70?

 

I thought 45 seemed a little high for the first pass. I did 25/45/68 with ARP head bolts and sealant. Haynes and chiltons recommended 22 on the first pass.

 

I did mine similar to his and never retorqued my head bolts and I was fine