spark plugs

[67belevdere/225]

what plugs and gap do I run. I have 9.5 compression running twin carbs and headders
and mopar electronic ignition. what thermostat would you run in it for break in and after
thanks

 

[cdnEHbody]

Ngk zfr5n. Nice long reach. Only in drool tube heads. Washers removed on the plugs. I have stock compression, but run hei ignition. Can't remember gap...

Not sure if those plugs will interfere on a shaved head with anything fyi.

Edit. I run .040 plug gap.

Can't answer thermostat. Sorry.

 

[Darter6]

Slants like heat (in my experience anyway) if your manifold has no heat provision I would run no less than 180.I got best results with a 195. Looks like you are in cold country.My Slant drag car I would leave the line at no less than 180 and ran best between 185-190 at the line.

 

[slantsixdan]

To answer the spark plug question helpfully, we need to know which type of cylinder head you're running. Is it a '60-'74 head (with the aluminum spark plug tubes and the gasket-seat plugs) or a '75-up head (without plug tubes and with the smaller taper-seat spark plugs)?

Thermostat: a Stant SuperStat 45358 (180°) or 45359 (195°) after reading this.

 

[67belevdere/225]

To answer the spark plug question helpfully, we need to know which type of cylinder head you're running. Is it a '60-'74 head (with the aluminum spark plug tubes and the gasket-seat plugs) or a '75-up head (without plug tubes and with the smaller taper-seat spark plugs)?

Thermostat: a Stant SuperStat 45358 (180°) or 45359 (195°) after reading this.

67 with tubes shaved head . 100. and running twin carb from Clifford performance

 

[slantsixdan]

Ditto the recommendation for NGK ZFR5N, then. Gap 0.035" to 0.045" depending on what ignition system you're running (see HEI upgrade ). Remember to remove and discard the metal ring washer from each spark plug before installing it.

 

[67belevdere/225]

will do , I saw the upgrade and have that same coil and pick as a spare from our pick up , I guess I'm gonna upgrade
that hei gm ignition sure is hard to beat
thanks