What is the difference between 44ts & r45ts
 

Whats the difference in the r44ts and the r45ts?

Thanks

AC R44TS is a colder spark than an AC R45TS... i think with hei you can go hotter with the spark, it might help with oil fouling if your mototr is worn out . but they will both go in and run, almost no diffrence IMO

in my stuff i always run R44's, i dont really know why... i just do :D

i know with nitrous applications most guys run like an R42, or somthing similar

I have always ran a colder plug in a vehicle that sees a lot of highway miles and a hotter plug in a stop/go or oil burner.

The prefix R refers to Resistor type, 44/45 are heat ranges. the stock plug for many 73-87 SBC is usually 45. The suffix's on the end refer to how the plug looks on the bottom. Dont have the book with me but a TS is a tapered seat with smaller thread size 14mm I think. The AC R43 was the plug for older SBC point style ign. With my HEI upgrade I moved to A R45 to match the heat range of the early Hei SBC.

http://www.acdelco.com/html/catalog/index.htm

I ran 45 the last time,and went to 44 this time and it seems to run better.Maybe it's just me.