sped921

Hello everyone. First post and I need the forums help. Recently bought a 1965 vert, stored in a local garage for the last 25 years. Brakes, fuel,ignition,cooling systems have been rebuilt to provide a safe weekend driver. NOM motor which is a 1971 350 block with GM 492 angle plug heads. I have rebuilt an HEI dist and used the set-up by Lars to get the timing sorted out. She runs like that first hot rod you drove in when you were 16, WOW. I want to make sure I have the correct spark plug in there to match the heat range needed. I don't know too much about the motor other than roller rockers up top, unknown lifters, Holley dbl pump carb, 36'total mechanical timing with an additional 10' from the vacuum can. I tried the AC 45S but they are the large diameter plug and do not fit the 492 heads. Does anyone have any suggestions as to which plug would be a good starting point? I am still taking short trips to perform the shakedown on the car so reading the plugs may still be a little premature at this point. Thanks everyone

Eddy

GCD1962

Champion J12Y

sped921

Thanks so much.

Old Blazer

I use AC R43TS plugs with my 492 heads. The engine is an LT-1 with 11:1 compression. Should work for you too. If they foul out use the hotter R44 plugs.