What plugs are you running with your HEI distributor? and what do you gap them at,thanks

 

i was running the r45s in my 72 350 with points and a .040 gap . i changed over to hei and kept the same plug in it .The motor didnt seem to care.When i do a plug change which will be soon i will jump up to a ac delco r46sx .ill keep the gap at .040 .

 

Use the same plugs that you were using with points and open the gap to .045

 

X2 on the .045

 

Keep the same gap or a slightly bigger. A wider gap increases the size of the flame kernel and can contribute to pre-ignition.

I wouldn't switch to the plug intended for a wider gap (SX) but not increase the gap, either stick with the same plug and increase it 0.005" if you'd like OR go the wider gap plug (SX) and use the spec for which that plug is made.

Good luck!!!

 

The original R46SX comes with an .080" gap. The R46SZ comes with a pre-set .060" gap. The .080" is too wide and will end up killing your HEI components. This is why they replaced the R46SX with the SZ.

Keep it at or under .060 and you should be just fine. .045 isn't bad, either. Just depends on how emissions friendly you like to be.

 

thanks guys