CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Spark plug gap for 75 GM, 250, 6 cyl.?

Eric M.

1/2 ton status
Joined
Dec 10, 2001
Posts
2,142
Reaction score
3
Location
Oakland, CA
Anyone know the correct gap for the spark plugs in a 75 GM, 250 ci. 6 cylinder engine?

The specs. found on the sticker under the hood are long gone. I'd pick up a Chiltons manual, but the trucks hardly worth the cost of the spark plugs already!

Thanks,

Eric M.
 
Last edited:
thirty five thousandsths.....

I believe all 6 cylinder chevy's plugs are gapped at .035--points or HEI....some 75 only GM vehicles used wide gap plugs set at .060 or .080 ,but only on V8's ,and they reduced the gap on them to .035-.045 in 1976 after a lot of complaints about hard starts in cold weather and the plugs getting wet and flooding too easy..those ac plugs that have extended gaps had the suffix TSX at the end of the number...I'm 99 % sure the inline 6 cylinder motors always used .035 as the gap setting on the plugs...... :crazy:
 
Top Bottom