Best Spark Plugs For The 429 Cadillac V-8??

[David Cotton]

Just curious what consensus there is on the best spark plugs to put in our 1964 Cadillac 429 V-8. Looking for brand name etc.. Thank you.

[David Cotton]

Thank you, for your time to check for the number.

[David Cotton]

Yes- already purchased them- Many Thanks.

[David Cotton]

Thanks Everyone- much appreciated.

[David Thomas]

I've been using the Autolite AP85 in my 63. Closest heat range I could find to match the AC44 that came in the car. The standard Autolite 85 would be the same heat range.

[David Cotton]

Excellent- Thanks Jason. That is just the info I needed. Much appreciated. If I cannot find them locally, I will order them from you.

[Jason Edge]

I ran Bosch Platinum and high performance plugs,   some hotter and some colder heat range, but went back to the old standby and use a Champion Copper RJ12YC.  Seems to run like a "champ"... no pun intended. If you need any of these I sell for $20 a set and have about 8 sets on hand.  I would have to go back and look at heat range (I think the 12 puts it a bit toward the hotter range as I recall?) of this plug but it seems to work well on my 64 CDV. I could  not tell ANY different from using these vs the platinum plugs.  It was what was cross referenced by Champion for the car and that is what I use.