Fenderwell exit headers in progress

[Poison Heart]

haha then you're pretty close to getting headers to fit! Of the 4 sets of headers I've tried only one hit the steering box and damn near everyone hit the starter and had to be hammered.

[starchief1959]

What headers would fit with the mini starter? And I'm not interested in shortys. Might as well leave stock manifolds on if they're shortys.

[Poison Heart]

Well, The first set of headers I tried were Summit. I think they barely hit the starter but cleared the steering. The second set I tried were Hedman somethings, they hit the starter pretty good, cleared the steering box but hit the pitman arm. The third set was the Hedman 3 tubes which cleared everything but were really close to the starter.

Of course all of those hit the frame. You'll have to figure that part out. You can go under the frame like I originally did.

I'll double check the hammer marks on my old headers and see if I remembered all that right. I guess I've only had 3 sets, not 4.

[mrpontiac65]

Was there any way you could cut a hole thru the X-frame and run them, I need to look at the pictures again.

[starchief1959]

Ya, could go right through the frame. I was thinking about that.

[Poison Heart]

Yeah, through the frame would be the best way

[Trump]

question: I haven't messed around with too many post 1965 pontiacs. Do the same header flanges work for all models 1955-1979 or was there a change in there somewhere. I am working on a gasser project and will most likely be making my own headers as well. Hoping to find an old set to use for the flanges and collectors and need to know what will work. Thanks.

[Poison Heart]

Most of the Pontiac heads were "D PORTs" but somewhere in there they had "round ports." I think some of the 62-63 SD cars were round ports. I don't know which else were round ports. I paid like $80 for my flanges off ebay. They were a bitch to get those tubes in there. Especially the middle "D ports." You might be better off finding a set of cheap used headers to use as parts as you stated.

What kind of car is it going in?


Good luck!

[poncho1961]

I'm thinking 68 RA II, 69-70 RA IV, 71-72 455 HO, and 73-74 455SD were the round ports, all others being D port. All round ports are interchangeable with other round ports, and all D ports are interchangeable with the other D ports.

[Poison Heart]

Thanks for the info

[mrpontiac65]

Originally Posted by poncho1961

I'm thinking 68 RA II, 69-70 RA IV, 71-72 455 HO, and 73-74 455SD were the round ports, all others being D port. All round ports are interchangeable with other round ports, and all D ports are interchangeable with the other D ports.

With one exception- '63 SuperDuty Heads had D-Ports but the exhaust mounting holes around the two center ports are wider.

[Poison Heart]

Those are some cool heads

[mrpontiac65]

Originally Posted by Poison Heart

Those are some cool heads

The '63 Super Duty's were mine (ex- Arnie Beswick's back in the day) and now back to him.Here's some more pictures of the "980's" and Super Duty Exhaust manifolds.

The others are from E-Bay and other sorces. Every chance I get to get a picture of some good parts I save them for reference uses.

[starchief1959]

Since we're discussing SD heads. Don, was there any difference in the standard heads and the SD heads in 1960 other than the larger intake valves?

[mrpontiac65]

I think that's all it was.Not sure on those.

[mrpontiac65]

'59-'60 SD 1.92/1.66 69cc's casting no.540306 part no. 540304

'61-'62 SD 2.02/1.76 67cc's casting no.544127 part no.540124

'63 421SD 2.02/1.76 64cc's casting no.9771980 part no.9771983

[starchief1959]

Thanks don. I've been planning on rebuilding my heads but didn't know if there was anything that made the SD better. I'll just port the heads and put in bigger valves. Will save me time and money not looking for the SD casting number.

[mrpontiac65]

Originally Posted by starchief1959

Thanks don. I've been planning on rebuilding my heads but didn't know if there was anything that made the SD better. I'll just port the heads and put in bigger valves. Will save me time and money not looking for the SD casting number.

Just don't port them this much, back in the day with a Blower they thought bigger was better. They just hogged this one too far, wish I had a matching set, they would look kool!

[starchief1959]

Since I have to have my machinist do the valves I'll probably just let him do the porting too. Then I'll just gasket match my intake.

[The Chief]

1955 are round port on the outside and Siamese round port on the center