Slant header ID?

I told ya so...:D..

Yeah, whatever... :(

Just a FYI. Back in the day, Clifford had at least 5 different headers for the slant six. Year and body style was the determining factor.

Interesting, I had no idea there were that many. I sent these photos to the folks at Clifford to see if they can help.

Now see? IF You'd only angle-milled the head for maximum squeeze, You'd be golden! Lol!
Odd there isn't one stamping anywhere, but it wouldn't take much of a tweak up top to make 'em move a bunch below, I'd wedge a block somewhere & heat the tubes near the flange 'til it relaxed. May take 2 or 3 steps, IF they actually fit the chassis they're destined for. Paint be damned!

Haha, I don't think this truck would know the difference if I went for max squeeze or not. They need a lot of clearance, the bottom of the flange is at least 1/4" away from the head on the front half. The back set has about a 1/8" gap but I think that's due to being pushed outwards by the front half. Before I am tempted to modify these, I will give them a test fit inside the truck to see what happens.

Here's the gap at for the front half.

DSCN1002.JPG

And the gap for the rear half.

DSCN1003.JPG

Hooker Headers use a thin flange. I would say they are older Clifford models.

Agreed, the flange on these is at least a half inch. Hookers, IIRC, were more like 3/16".