What spark plug do you recommend?

[T2R9]

Autolite 64's

I agree. I switched to Autolites years ago on both small block and big blocks. Great plugs. I run my gap at .35 with points or .40 with factory electronic with a good coil and wires.

 

[SUPERSTOCKRACER]

Champion J-11Y in a big block

those are the correct assembly line plugs, but they dont sell that range anymore.
just go with the champion j12-y, thats the new cross reference number. i have has great results with a tad hotter plug. j12y's for me in all my 440 wedge motors.