AC 44 or R44, or the equivalent interchange number for Champion or NGK. NOT 44T- - - -that's a tapered seat plug with a 5/8" wrench size. 44 has a 13/16" size and a flat copper gasket. AC 45 is OK if you don't do a lot of high speed highway travel. It's a little hotter than a 44. The "R" prefix indicates "resistor"- - - -either one is OK. RUN- - - -do not walk away from Prestolite plugs.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!