[shinysun]

I have a question on the 2 plugs.

The specs are almost the same for each other except "projection"

6510 has 0.043" gap while 5107 has 0.05" gap, seems 6510 is close to the genuine spark plugs' gap (around 0.04").

The thing is the manual of Whipple supercharger.

It recommends using 5107 and making the gap reduced 0.032"

Is there any reason for that? and seems it is more reasonable to use 6501 and make the smaller adjustment.

and I am using only 9~11PSI (planning), should I adjust the gap? or leave it like 0.4" around. It is quite confusing. Ted said 0.039~0.04 would good for more power due to the system is different from other vehicles while Whipple said 0.032" is recommended.

Thank you.