Should I put the plugs in before or after the header install? Before sounds easier but more likely to break one off on the header install huh. Whats yalls opinion?

 

Get the old manifolds off, get headers in place but not bolted in. With the headers in this way you can still move them around to gain more clearance when working with the plugs. After you have the plugs tightened down, then is when I would bolt the headers up.

 

I put them in after, it took alot of fighting to get the headers in. I made the mistake of leaving the coolant temp. sensor in and I crushed the plastic housing on that pretty good. If you do the plugs after, it is one less obstacle in my opinion.

 

Ya, Too late for the sensor. I busted it all to hell already. The header bolts on my driver side are cross threaded at least 2 of them are, number three and the one at the back. I am going to pull the head off to fix them. Im going to use a tap I guess. Any tips?

 

If the tap doesn't restore the threads than helicoil it.

 

Can you even install headers with the spark plugs in? I don't think I caould have with my headers. Regardless, I would recomend pulling the old plugs, installing your headers, and then add the new plugs. Also, buy a 3/4" rachet wrench and the special F-body spark plug socket...makes life much easier!!

 

Like someone posted before, get the headers in place. Then put the plugs in. That way you still have some time to move them around to get the plugs all screwed in. Also, you would certainly snap off some of the plugs trying to wrestle your headers in, ESP no doubt if they were LT's. It is not possible, to my knowledge. After definately.