spark plug for stock 502?
 

I'm wondering what kind of spark plugs to get for my 502 mag. Stock (rebuilt), carbureted.

I searched the forums and found references to a projected tip design providing the best results. There seem to be a lot of recommendations for the NGK BPR6FS or the BR6FS, and also for the a/c MR43TS

Should I go with an extended tip?

Will i have any issues with piston clearance?

Will I gain anything?

Yes, you can use the extended tip.

Also consider the A/C RapidFire part # 1

Champion RV12YC, AC MR43T or MR43TS, NGK BPR6FS. The plug basically goes in perpendicular to the piston so xtnd tip clearance is not an issue. .045 I believe.

Thanks guys

I'll go with the projected / extended tip NGK or a/c

I dont know if the BR6FS is extended or not. If not, I dont know the extended's model number.

from other threads, the only difference between the NGK BR6FS and BPR6FS is that one is extended. I think the "P" stands for projected (extended) but i'll double check before I buy the plugs.