I haven't changed the spark plugs in my 91 corvette since the 396 engine swap 30K miles ago. They need to at least be examined. My AFR (running open loop) went from 13 to 16. I replaced the fuel filter, checked and changed the fuel pressure, and checked all other ignition parts. The engine doesn't run rough and all cylinders seem to be working.

What is the best way to change spark plugs with headers? Do I bend wrenches so I can get at the plugs or disconnect the header? How big of a job is it to disconnect the headers? Should the header gaskets be replaced in this process?

 

This forum is exclusively for 3rd generation F body's: Camaro's and Firebirds. Most of us don't know or care about working on a Corvette.

http://lmgtfy.com/?q=header+spark+plug+socket

GD

 

There are always lots of tips and tricks to accessing items like plugs, Beth. Above, through the wheel well (n/a on a '91 Vette), or from below, with a swivel, short socket, etc., etc. As mentioned, everyone here is focused on 3rd gen. F-bodies. You need a Corvette forum. Perhaps one like this.

https://www.corvetteforum.com/forums/

It has a section for each generation. The C4 section has many posts from today in every section, so it looks like a fairly active place. Give 'em a try.

Good luck with your project.

 

What Dave said. I hang out over there. Great group of car fanatics over there.

 

Passthrough ratchet and plug socket.