i've put down what I think is correct, but please feel free to correct me. I can't seem to find this data all in one place and would like to compile it.

NGK Denso Beru Autolite
stock tr5 IT-16 ? ?
+1 tr6? IT-20 ? ?
+2 ? IT-22 ? ?
+3 ? IT-24 ? ?

thx!

 

also, how about a guideline for spark plug range and boost levels for stock and aftermarket?

eaton

10 psi
12 psi
14 psi
16 psi

KB

16 psi
18 psi
20 psi
22+ psi

 

the only plugs I will use are NGK TR6's
thats with 22# of boost on my KB

most trucks .038 gap will work
when you get into the higher boost reduce the gap to .032-.035

real high boost .028-.030