A/C spark plugs

[Harmon C.]

What is the difference between (AC-44-T)---(AC-44-TS)and AC-R44-T ACNITER?

[Clem Z.]

Re: A/C spark plugs

"T" is tapered seat shell. "TS" is tapered seat shell with extended tip, "R" is resistor type plug

[Harmon C.]

Re: A/C spark plugs

Clem Will they all be OK to use in my 73 350? What is the reason one would use the extended tip. Lyle

[Clem Z.]

Re: A/C spark plugs

the correct plug for your 73 corvette is the R-44T. the 44T could cause static on your radio because it is a non resistor plug. the entended tip plug will burn cleaner BUT to be sure not to cause any piston to spark plug ground electrode interference you should "index" the ground electrode so the electrode is in the 7-12-5 oclock position. you can do this by marking the insulator of the plug with a magic marker in line with the ground electrode and after installing the plug look for the mark and as long as it is not at the 6 oclock position(bottom) you will be OK. if you end up with a plug at the 6 oclock position exchange it with a plug from a different cylinder till you get all plugs away from the 6 oclock position

[John M.]

Re: A/C spark plugs

Hi Clem,
I have a 71 454 rebuilt with 71 heads, comp cam and 9:1 compression ratio in my just completed 67. When I was breaking it in a couple of the R44T plugs got wet, float problem, and would not dry out while it was running. Would the extended tip be OK for this engine? I would think the 9 to 1 would mean yes, but I didn't build this engine.
BTW my nephew is on the NO.16 car on the Rausch team as a manager. He was the differential guy for Matt Kinseth last year. My other nephew was the chassis guy for Dick Trickle a few years ago.
Thanks for any advice,
John McRae

[Clem Z.]

Re: A/C spark plugs

you can run extended tips in you engine and i would use 45 because the fuel wash keeps the extended tip cooler than the standard tip plug