influence

I have gt40 heads on a stock bottom end the heads have new valve train and the valves were lengthened(I believe I cannot get ahold of the guy that did the set up so now Im stuck)...I decided to change the plugs today and found #5 Black and Gunky. I pulled the plug: AC Delco 41-985 When I went to Kragen they only could cross reference this to an champion double platinum. It seems these plugs fir a Z06 Vette and other misc. chevy trucks.

So I am not sure what to do...dont know if there will be any clearance issues or what gap should be...I believe the gap is set at 50.

Any help greatly appreciated since the car is apart.

Thanks in Advance

nitrous_bob

just clean it real good........ i like small gaps, stock is .052 and i like about .045"

kaggriff

an autolite xp5245 or an ngk 1465 are the same plugs also

Timspony

Gap ^^^ looks good, I like the Champion RC9YS4 or RC12YS4 ...the 9 is a colder plug...

influence

when it comes to plugs I am not too educated.

Is colder or hotter better. I am not supercharged nor am I NOS deep in tha house...so

Its N/A baby all the way...okay anyways which would be better?

Timspony

Champion RC12YS4 is the stock NA heat range

ih8chevy

If ur running alcohol then u want hotter plugs. On gas cooler the better.

projectresto83

Just go look for a plug for a 95 lighting. Standard autolights are like 1.69 or something like that and run great. I just put my gt40 heads on and used them and I don't have any problems yet. Just need to tune my carb again though lol.