Originally Posted by
MOP
Last spring after three faithful seasons on my AC 43T's I decided to try NGK BR6FS supposedly the direct replacement for the AC's. Boat has been running decent but I got a bug to check the NGK's, I put about 35 hours on last year. When I pulled the AC's out last spring I had that why bother feeling, they were spotless with -0- signs of tip wear. Upon pulling the NGK's it was easy they were a colder plug, they were a good color but a bit cruddy. They were not handling the 750 Holley well enough to suit me, they would be fine in a 650 or under engine. Bummer is I was handed a new set of NGK's over the winter so I stuck them in but will put my faithful AC's back in next season. Do no take this as knocking NGK they are a very good plug but BR6FS in not good for a 383 with a 750 Holley.
Originally Posted by
cvx
I was a little suspect of my NGK's too, ran the same set of AC's for 3 years in a similar engine. Then when I built my 406 sbc w/Dart heads,770 Holley. I installed R5671A-7 NGK's. Now at least 2 plugs foul at the beginning of each season. Think I'm gonna replace the NGK's with an AC equivilant.
Hey Phil & Jeff,
You know the old saying: If it isn't broken don't fix it!
My small & big block Chev's in both boats luv those AC 43 TR's too!
This year I only replaced the cap & rotor after doing my ign check inspection.
Think Fast, Live Long!
Humor Helps.