John Starr

I have a 63 327/300hp and judging manual calls for AC44 plugs. A few years ago I bought AC44TS plugs with the green rings and haven't installed them yet.
What is the difference in the plugs? What are the pluses or minuses with AC44TS I have?

begee22

I'm not a spark plug expert ...................surely they will chime in with comments. I believe AC44 are too cold for normal condition driving and I have installed 'old' AC45S plugs in my '63 300hp A/T and they seem the correct plugs for my car. Another alternative comparable plug is an NGK-B4 that many here have had good results with. begee22

Dave Strickland

John,
TS is a tapered seat plug with an extended tip (S). Different thread size for your car.
Not for any pre 71 application. I’m an AC advocate and I have AC 44’s in my 300 HP 63. Could use 45’s (hotter plug) or S (extended tip) or both.

jim lockwood

The big minus is that the 44TS plugs won't fit your 327 heads. You can't use them at all.

R45 or R45S plugs are what you want in the AC product line.

John Starr

Thank you for your info.