[Maximus21]

hello folks
65 ss 396 l35 completely stock with the exception of a pertronix d100700 distributor, 45011 coil, any suggestions as of what spark plug and gap i should be using?
Thanks

 

[jayoldschool]

Stock plugs, gap to 035.

 

[Big Dave]

A repost of one i wrote back in May of 2008; but the information is still the same.

An AC-Delco 43-2XLS will work if you can find one (NGK BPR7ES interchanges). Starting in 1996 AC-Delco renumbered all of their plugs using only numbers to form an undecipherable matrix to assure no one used any of their plugs except as a direct replacement as the heat range information was lost. With an AC-Delco plug the bigger the number the hotter the plug. The old code was contained in this information I cut and pasted from AC-Delco's web site:

The ACDelco Spark Plug Identification Table
Prefix and suffix letters are used to identify a specific type plus the numbers relate to thread size and heat range. For example, the R45TS spark plug shown is:
· R = Resistor
· 4 = 14 mm Thread
· 5 = Heat Range (range 1-5 start with a 3)
· T = Taper Seat (No T for your gasketed plug)
· XL = Extra Long Reach, 3/4" fully threaded
· S = Extended Tip

I agree with the spark plug gap as well though if you go to an HEI (pertronix isn't a true HEI) gap it for 0.040"
Big Dave