Spark Plugs - Which?
 

1980 911SC 3.0

The rebuild result will be:
3.2 10.5:1 Mahle p&c's
964 cam
Clewett's Electromotive TEC-3r distributer-less ignition system
EFI thru a 1984 Carrera intake manifold
Dual Spark Plugs
SSI's

It's been recommended to me to use 'Any # 5 heat level' Spark Plugs...

I'm inclined to use NGK over Bosch plugs, and not platinums

Questions - assuming NGK's - and considering that the lower the 'heat level' number the hotter the plug:

> Are 5's too hot for this engine?

Note that NGK's website product selector results in:
1980 911 3.0 = BP7ES
1984 911 Carrera 3.2 H6 FI = BPR6ES

And, the Pelican site has:
911SC 1978-79 = BPR5ES
911 1980-83 = BP7ES
911 Carrera 1984-89 = BPR6ES

I'm so confused....

Advice? Experience?

Thanks very much

Jim

I use BPR6ES in my single plug 3.2 with 964 cams. The NGK number system is backwards (opposite) to the Bosch one.

Jeff