I got my 383 started up for an initial run-in and it's cooling down now. I am going to retorque the heads because I am using Cometics, and I heard to back the nuts off 1/4 turn, then retorque. But do I back them all off 1/4 turn then retorque in a normal pattern, or do I back each one off 1/4 turn and retorque them individually one at a time? I'm thinking it's one at a time, just not sure.

 

OK, I found another source who said to do one at a time, so that's what I'm doing.

 

I'd call Cometic and ask them what they recommend. Most of the better engine builders I've spoken to said not to retorque them.

 

Shouldn't have to retorque an MLS gasket like the Cometic, though it won't hurt.

Rich

 

Well, I thought it was mostly due to the head studs not being heat cycled. Anway, I retorqued them one-by-one, a pain considering the headers and the rocker arms had to come off again, but I got her done and it's running well so far as I can tell. I am going to take it out & beat on it next and break in those rings.

Appreciate the advice. thanks.

 

Huh, shouldn’t have to retorque, but if you do it you’d have to back off all of them at once to duplicate a proper torque sequence.

Real world, I’d be surprised if it mattered, the only reason that you’re backing them off is to break the friction so that you get an accurate torque reading with the torque wrench.

 

Mark, what I ended up doing was loosening them one at a time and retourquing them back to 65#. Some seemed a little tighter than others when I was loosening them, even though I was very careful torquing them in the first time. I figure, you're not trying to spread out the gasket load during the retorq as much as you are trying to get the right stretch on the studs, and now that there's 100 miles on it and no problems, I am beginning to think it will hang together for a while.