What kind of plugs would be suitable on a 454 with 781 heads. I am running MSD ignition 6AL/distributor?

Thanks,
Joe

Hmmm, ACs come to mine, say the stock plug to start with. Far to many people think you need cold plugs in motors with a little work done on it. You should start with the sock plug and go from there, and no I don't know which one it is.

Go ask one of the 400 pound gorillas at Autozone, you know the one with the chip on his shoulder the size of a redwood tree!!

Joe,

If I remember correctly, all stock BB used AC Delco 43's, but I'm not sure about the 454 HiPo's. The pre 70 BBC (non-454's) used the flat 13/16 type plugs (R43's or 44 or 44N's). 1970 and later used the 5/8 tapered plugs, I pretty sure that they were R43T's for the 454. If you change the horsepower, compression, etc, you may need to go to a colder plug. Hopefully someone will set me straight on this, but I believe that for every 80 - 100 hp, you drop your spark plug one step colder, if it's naturally Asperated. The following may be helpful, it's for the year 1971.

454 - 345 hp, points used, R44T
454 - 390 hp, points used, R43T
454 - 450 hp, Transistor Ign. - R43XL

Fred.

i was in msd web site on the tech forum checking in to this as my plugs look to be to hot and there saying one to two heat ranges colder and .050 to .065 plug gap up to 10.5.if you need more info on this just check out there web site and the tech forum.



chris

Hmmm, ACs come to mine, say the stock plug to start with. Far to many people think you need cold plugs in motors with a little work done on it. You should start with the sock plug and go from there, and no I don't know which one it is.

Go ask one of the 400 pound gorillas at Autozone, you know the one with the chip on his shoulder the size of a redwood tree!!
Oh, you mean the one that knows all there is to know about cars????

Oh, you mean the one that knows all there is to know about cars????

That would be the one!!! It must be a requirement to work ther!