Small Block & Big Block Chevy Specific - HEI spark plug gap??

I tried searching... sorry.

what plug gap are y'all running with HEI? I just swapped one into my Jeep's straight-6, and would like to know how wide I can go. Thanks.

Well for normal operation and no ign boost, a .040 is generally recommended.

Now some of the Buick and Olds use a long tip plug and they go .060.

The plugs for my chev motor come pre gapped at .40. With a fresh stock HEI (aside from taylor wires and msd cap/ rotor) it seems to handle .55 ok. @.60 it started to miss when I wound it up past 4000 or so. Keep in mind the higher the gap you go with the faster you will burn out plugs.

Gotcha, rat. The motor won't see anything over 5000 rpm, so I'll probably go something like .045". I've always liked the middle-of-the-road approach. Thanks for y'alls help.

I always gapped mine around .045-.050. This was on a mild 350 engine with about 375 hp.

Derek