So I'm finishing up my winter maintenance, and I'm in a spark plug dilemma. 2002 500efi manual calls for BR6FS, but there are extended reach BPR6EFS currently in the engines.

What is the correct plug? Should I stay with the extended reach NGKs? Don't think it matters, but the top ends were done a few years ago, is it possible the heads were replaced with the later style GM heads that require long reach plugs?

Boat ran great all season, so I'm inclined to swap the BR6FS for the long ones. If it ain't broke, don't fix it!

Thoughts?

Br6fs in 500 efi
Bpr6es in 525 efi

I think I have 2 complete sets of those new in the box at the house (for the 500's I once owned in a 382). I sold the boat and they are just sitting on a shelf. I'll check tonight but let me know if your interested in these.

Thanks, guys.

Since they have the 525 spark plug that means they must be 525's, right?


T500hps - Which plugs do you have? I have 2 boxes of BR6FS per the manual, but when I went to change them today that's when I discovered the different plugs.

Well, not the same plug. These are the plugs I ran in modified 500's (540's with heads/cam/intake work). I have 16 NIB, If you can use them let me know.
NGK BKR6E

br6fs if it is stock,the 525 has an edelbrock aluminum head.

Thanks guys. I'll stick with what the book says and go with the BR6FS.