HEI

Not sure about passenger cars, but a '73 pickup still had the "window" distributor with points.

nate

late 74 on some models. 75 across the board.

If my memory hasn't completely failed me, Cadillac had the first HEI in '74, and the other GM makes had it in 75. It's possible Cadillac had a few HEI units in 73. Maybe my CRS syndrome has failed me......

Thanks ,bought an old truck with a pontiac motor & it has a breaker point dist in it. Looks like an older restoration with a Nova (or probably ventura) subframe welded in at the front. Traced the engine code to narrow it down to a '73 400 or a '74 455 all other engines using a Y4 code are 76 & 77, so providing the dist is OE, I've narrowed it to 2 choices. Will check the rest of the #'s to figure it out, Thanks again for the input.

There was also a breakerless non-HEI offered from 71-73 on some pontiacs called Unitized...