Port matching from the head to the header is critical for peak performance. The d port head looks like a set of ds mirroring each other in other words back to back.
Max Manifolds Pontiac 1964 67 Gto Lemans Tempest Ram Air
Round port headers on d port heads. Designed for all round port heads like the kre high port edelbrock and ram air ii iv and dci tiger head. Round port heads are exotic stuff only used on the highest. Hello guys if your looking for an exhaust system from the headers back with church boys 4 link here ya go. This is not a d port head but a round port instead. Compare the flow of your exhaust to a river. Should i off the headers and get square port headers.
You have to make a cut in front of the axle tube and add 1 for a little more clearance for travel up. I bought the flo master american thunder kit. The only other major variation in pontiac v 8s is found in the exhaust ports and here you have a choice of round port or d port. Arp cylinder head bolt kit round port pontiac v8 pn 190 3601 see more like this mr gasket 5966 exhaust manifold gasket set round port diameter 192 fits. Below is a picture of the edelbrock round port and d port heads side by side. These 2125 round port raiv exhaust flanges are cnc cut from 38 thick steel.
One would notice that the round port actually looks like a sideways d that is pointing upwards. I noticed that the heads were square port and the headers were round port. How will this effect my performance. Round port heads came on the highest horsepower pontiacs in 1968 1969 and 1971 1974. Do they make square port block hugger headers. They are much rarer than pontiacs d port heads because they were produced in limited quantities.
They will fit and the gasket shows that the shape is pretty close. If the header port is too small the flow would be similiar to whitewater if its too large it would be similiar to water flowing over a. Theyre called round ports because of the round shape of the exhaust ports which is the part of the head that connects to the exhaust manifold or header. Its not as much of an issue if the header is slightly larger but smaller is terrible. The first question is the ability to distinguish between the two types of heads. Great start for those making a set of 2 18 headers for your high port combinations.
Pontiac authorized mr gasket dealer. I havent noticed any square port block hugger headers in my catalogs.
Gallery of Round Port Headers On D Port Heads
