'68 L79 spark plug gap

[Dave F.]

Is .035" the proper gap for an AC R43 ?

[Duke W.]

Re: '68 L79 spark plug gap

Yes, but I recommend you use the R45. The R43 is too cold. I found it works well for race track hot lapping, but is too cold for the street. Even the OE R44 is too cold for the street. The R45 is just right.

Duke

[Dave F.]

Re: '68 L79 spark plug gap

Thanks Duke - off to the parts store. I may get this fired up today !

[Michael F.]

LT-1- this apply also?

Duke is this also a good plug for the 70-72 LT-1s????

[Duke W.]

Re: LT-1- this apply also?

Yes, AC heat range "5" (second digit of the plug number) is good normal driving plug for all small blocks regardless of displacement or power rating.

My own preference is either the NGK B4 or Denso W-14U, both of which are non-resistor and equivalent to the out-of-production non-resistor AC 45.

Duke

[Stephen W.]

Re: LT-1- this apply also?

That explains why the counter person gave me the r43 ( he did call to check the number), but when I pulled the first plug it had r45S in it(327/300). Sounds like your suggestion would be to switch it back to the 45.