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Have my 88 with the 383 i just built. I ran engine on stand with my Hedman hedders. 1 5/8 primary's, 3" collector. Ive had these in a box since 2002. These hedders fit great.
Heads are GM fast burns, with the .250" raised D port exhaust.
The gasket is a Fel pro 1470.
As you can see in the pic, the hedder is blocking the exhaust port by .200". The gasket fits the head perfectly.
Definitely not enough material to grind the top of the tube.
Was really hoping the stay with these hedders as they do fit the car perfectly. Im still waiting to get my full dual exhaust, so now is the time to find out if i need to get different hedders.
Ive read a ton of stuff on this situation, but mostly guys from the C3 forums...So block huggers and what not are out of the question. Want to stay with full length - as thats how i built the engine.
Any ideas? Will 1 3/4 tubes cover the ports?
Seems the only option i have with these would be to machine the bolt holes .200", so it raises the hedder up by that much. Seems the 1 5/8 tubes would cover the port perfectly if I did that...
Waiting to order dual exhaust from Malibu T Tops. They offer headers also. If i have to call and ask them i will, but i know some of you guys have the fast burn heads....Also used on the GM crate engines, so I know someone ran into this...
Im preparing to hear i need new headers. Save me. LOL.
Have my 88 with the 383 i just built. I ran engine on stand with my Hedman hedders. 1 5/8 primary's, 3" collector. Ive had these in a box since 2002. These hedders fit great.
Heads are GM fast burns, with the .250" raised D port exhaust.
The gasket is a Fel pro 1470.
As you can see in the pic, the hedder is blocking the exhaust port by .200". The gasket fits the head perfectly.
Definitely not enough material to grind the top of the tube.
Was really hoping the stay with these hedders as they do fit the car perfectly. Im still waiting to get my full dual exhaust, so now is the time to find out if i need to get different hedders.
Ive read a ton of stuff on this situation, but mostly guys from the C3 forums...So block huggers and what not are out of the question. Want to stay with full length - as thats how i built the engine.
Any ideas? Will 1 3/4 tubes cover the ports?
Seems the only option i have with these would be to machine the bolt holes .200", so it raises the hedder up by that much. Seems the 1 5/8 tubes would cover the port perfectly if I did that...
Thanks everyone!
Weld along the outside the header between the pipe and flange, and leave a decient sized bead, and then grind the inside of the flange and tube to tapper the exhaust into the header. Should work fine.
I did this on my 1-5/8 headers on my F-body when I ran the E-tec 200 heads on that car. They have the same raised exhaust port as the fast burns.
Last edited by bjankuski; Apr 24, 2018 at 10:08 AM.
When I switched to fastburn heads I slotted the mounting holes on my hedman's and I still had to do a little welding to get a good seal. Now I am using 1 3/4" lt1 headers and they fit the ports with no modifications. I did have to swap the steering intermediate shaft to the later C4 style to clear the front tube.
When I switched to fastburn heads I slotted the mounting holes on my hedman's and I still had to do a little welding to get a good seal. Now I am using 1 3/4" lt1 headers and they fit the ports with no modifications. I did have to swap the steering intermediate shaft to the later C4 style to clear the front tube.
What year is your car? Any chance you have a prt number on your headers?
Thanks
Fast burn heads and hedder question
