I'm changing my plugs tomorrow and was surprised to not find what the AC plugs should be gapped at. Also how many qts of oil does it hold?
Thanks for any help.

Greg

When in doubt use .035

Yea .035 and try five quarts unless you have a oversized filter.

Pulled the plugs today and they were gapped at .040
to .045? Lost 150rpm or so? It's a 1999 mpi 350 mag.
Maybe the computer is adjusting?

What plugs are you running in your 350? I've been using AC R43TS plugs. Is that a good choice?

I prefer MR43T AC plugs because they have a large diameter center electrode (us cruiser guys hate changing plugs), but the R43TS is a good choice because of the extended tip. If yours runs better at .040-,045, by all means run it that way. Basically, it's finding what works best for your engine.

Using AC MR43LTS. That's what was suggested by the Mercruiser parts dealer. .045 is the correct gap. I called Mercury this morning. Now I get to regap them all.