Originally Posted by jughed
I'll be doing the E85 change soon. Running 440-1s on a 540 @ 13.5:1. I like NGKs, and it was suggested that I start with the -9 heat range plugs.
The NGK -9 plugs are very cold for normally aspirated engines. I suggest starting with -8 for 13.5 CR. twocents
The -7 might even be fine for longer plug life.

1993 Daytona, 5.50 at 130mph (1/8) 1.19 sixty ft (PG). Link to 572 B1 - Part 1