I'll be installing a D1-SC procharger pritty quick and I like to know whats the part numbers for the 1 and 2 heat range colder (from stock) Autolite plugs?

 

Stock is usually around a #26 Autolite (stock cast iron heads- short-reach plug threads, no gasket, 5/8" hex nut). 25 and 24 would be 1 and 2 ranges colder, respectively. My "go to" plug for a performance street motor is the Autolite #24. Not just becuase it's colder but becuase it's a "semi-shorty" design that clearms most headers very well.