Spark plug query

[Mad4slalom]

Hi all, what plugs are people using and recommending in their 350’s mine is a 72 rebuilt motor with 9.75-1 comp , mild cam and iron heads 350 bhp.
Which ac delco plugs ?, currently has ngk equivalents. Many thanks in advance.

 

[Chuffer]

I use AC Delco 45TS in the 9.5 : 1 comp Camaro IROC -Z 305 motor installed in my car with no issues .

 

[Mad4slalom]

I use AC Delco 45TS in the 9.5 : 1 comp Camaro IROC -Z 305 motor installed in my car with no issues .

Thanks chuffer, the 45 ts are the hotter one’s ?

 

[Roscobbc]

Seem to recall thse people were quite keen on 'plug prices - Spark Plugs, NGK, Denso, Bosch, Champion | The Green Spark Plug Co

 

[Chuffer]

Thanks chuffer, the 45 ts are the hotter one’s ?

To be precise they are R45TS to give them the proper code and the 5 is the heat rating on a rising scale and a hotter plug . Hot rated plugs can cause pre ignition on high compression engines but I have not had issues with the 9 : 1 comp ratio . If you go with NGK be aware their heat ratings are in reverse order to AC Delco , ie lower the number the higher the temp rating .