Oval port headers on Rect. port heads?

[pismorat]

I am putting my 383 full roller stroker in my wife's '69 C10. It has GM Perf. heads with angled plugs and rectangular ports. I ordered a set of Hedman Hedders to clear the angled plugs, but they ended up being oval port...am I going to have a problem if I try to run these?

 

[pismorat]

Since no one replied yet, I assume it is a bad combination...

 

[folkenheath]

I am putting my 383 full roller stroker in my wife's '69 C10. It has GM Perf. heads with angled plugs and rectangular ports. I ordered a set of Hedman Hedders to clear the angled plugs, but they ended up being oval port...am I going to have a problem if I try to run these?

Did someone severely port on those heads? As far as I know there is no such thing as a rectangular exhaust port. There are D-ports. And all small block Chevy's are pretty much rectangular port intake ports, so no one ever uses that term on the small block. But either way, as long as you have enough material to pinch the header gasket and not leak they should be fine. If they are D-ports, usually the header will just be a little too large at the bottom, but still seal against the flat gasket surface underneath. Unless they are a large race D-port or something.

 

[Stomis]

Yeah in fact oval headers on a D port head is ideal. Creates whats known as a reversion dam which aids in exhaust scavenging with a free flowing exhaust. Basically it doesnt let the exhaust gasses cycle back into the head but instead aids in drawing more gasses out accelerating exhaust flow.

 

[pismorat]

Cool, so should I just get a good set of gaskets(probably metal) that fit the d-port so they will last and not impede the air path? Or do I get a set that matches the oval port?

 

[Stomis]

Cool, so should I just get a good set of gaskets(probably metal) that fit the d-port so they will last and not impede the air path? Or do I get a set that matches the oval port?

Get a set to match the ovals.

 

[4X4HIGH]

Almost all SBC exhaust ports are square with the exception of some Corvette heads that had a D shaped exhaust port.

I have found that the Fel-Pro 1444 gaskets work best on most headers.