Dog-Leg Port vs Rectangle Port

[greasyjeep]

My question is this.

Did AMC/Jeep offer any V8s (304-401s) in the 70s that had a rectangle port exhaust?

I thought they all came with dog-leg ports.

The reason for my question.

I just received my Hooker Competition Headers (part number 9402), and they have rectangle ports.
Called Hooker, they said they will seal if I use the rectangle port gasket.

The Super Comps come with dog-legs, but they are way too much header for my application. Plus they are real $$$$$.

Thanks

[LRRH]

AMC stopped using the doglegs on the 360 in 72ish I believe. 401s always had doglegs.

[JeepKahn]

My 79 360 has doglegs....

[greasyjeep]

I thought every FSJeep V8 (other than the Buick's) came with dog-legs?

[Hump]

Whoa, some serious confusion here. I'm not one for dates, but early 70's on all AMC V-8s had dog leg ports. I believe only the late sixties, real early 70's car motors had square ports.

[Bob Barry]

AMC went dog-leg in '70, I believe. Apparently major impovement on the rectangular-port setup, contrary to the superiority of rectangular ports in other makes, like BBC's and the W2 heads on the small-block Mopars.

[greasyjeep]

Follow-up to the above posts:

Will these headers work?
The guy at hooker said they would, but...
I lined them up with a spare set of heads I got and they "looked" like the would, but has anybody out there run them with success?

Would usually just give it a shot, but a big time investment and I can't do much with them if they don't work, so...

Thanks Again

[Kris]

Originally posted by greasyjeep:
Follow-up to the above posts:

Will these headers work?...They will bolt up.
Should you bolt them up ?
I wouldnt, there are other companies that make headers with the proper shape port for the dogleg heads. Hedman is one, I have never used them but I know that others here have.

All AMC v8's went to the dogleg head in 1970. Contrary to popular belief, the rectangle port heads are not junk. At lower rpm's there is almost no difference in power. At higher rpm's the doglegs flow better because the floor of the port is shaped in a way that the exhaust flow bends down toward the manifold rather than bending up into the top and making a sharp turn down into the manifold as the rectangles do. There was also a small increase in valve size in the later heads, contributing to the increased flow.
smile.gif
kris.

[Cliff]

AMC switched to the dog-leg port in 1970, and they used it through the end of production. Do not use the Hooker square port headers - they make a dog leg version. Get the ones that match, or go with Hedman. The dog leg flows considerable better, and the wrong headers can influence the air flow.

All 304, 360, and 401 were dog-legs. 390 68-69 were square, in 1970 they had dog-legs. The 290 and 343 were all square port.

[billyrb]

My understanding was that the dogleg heads flow the best for our engines. Adding headers only adds top-end power, but at the expense of losing low-end torque. Every shop and builder I spoke to before building my engine said to steer clear of headers, unless I was racing the jeep.