spark plugs

[davestang67]

my 67 mustang has a 289 engine and basically stock. it has the pertronix ingition module. i was wondering how wide of a plug gap i should set to increase power. i have been running about a .035 gap (autolite platinums). also, if i increase the plug gap do i need to adjust the timing?

 

[D.Hearne]

Don't ge more than .045". I doubt you'll be able to feel any gain you get from a gap increase.

 

[rbohm]

i agree with DH, although i think that .045 is a bit wide. i usually go with .040 gaps.

 

[2nd Mustang]

I have a Unilite distributor conversion and gap my plugs at .045. I never have a problem and it also helps the plugs even with two cylinders leaking some oil.