Originally Posted by
largeorangefont
Sounds like you have the RB pipe, so no worries about quality. That header is the 92mm one. It is considered "short" but that is the one you want to run. Get those 1.1 springs on and it will be better. Also try fattening up the bottom. What plug are you running? if you are running the RB 6 get that out of there and try a MC-8 (possibly a MC-9 if you are running 30% without an extra head shim). That will help with the bottom as well. I put a 6 back in my engine once, and noticed the difference right away.
The plug is a OD 99. and I'm running OD fuel 20%. When you said mc-8 are you talking about a McCory plug. I have been adjusting the lsn trying to get the motor to have a steady idle may be to lean on the bottom. Glad to know the pipe is correct with the header.