I have read that extended tip plugs are not recomended on blower motors. I am in the process of installing a B&M 174 on a 461 chev. What plugs are you guys running on your blower motors.

start w/ mr41t's i personally like the NGK's better croos them w/ the r41's.

they maybe br4sf's...but don't quote me on that...it's a start...we just have a ton of them on board...

I had Nickerson Performance rework the carb on my blown Formula & Dean recommends NGK plugs & NO extended tips!!
So far, he has been right on with everything he has said or recommended. My .02.

I run AC's MR43T.

Which is the colder plug, the 41 or the 43.

41....by a lot is the cooler one...if u have issues idling w/41....look else where...pleople make the mistake a plug for idle not wot...u may need or should have an msd any way....u should have no problems w/41's as a starting place

I might be way off but I run a 174 on a 454 magnum with the MR43TS's and have no problems whatsoever. It's got a worked Nikerson Holley too. The original plugs were MR43Ts. I'd run the stock plugs and then pull them, then decide to go cooler if the color is not good. The stock 43 specs have a lot of leeway in their application. I have an MSD and Blaster coil also. You might also consider your boost, the more boost, the better the chance of detonation, hence the cooler plugs. Those 41's - do they faoul up on you on during long no-wakes?