Im trying to find the size difference between the 1-5/8 d port and the 1-5/8 round port headers. I was wondering if its possible to port the round port headers to fit d port heads.

thanks

 

Nobodys ever tried this?

 

From what I have seen gasket wise the round ports will cut into the edges of the D port. So from that I would guess that you would have to file the round headers in maybe four spots so as not to block parts of the D ports. Next question is if this is true is there enough material on the round port header to do it?

 

Actually I'm in the process of modifying a pair of Edelbrock headers for a Monte Carlo to fit my 87' Bird with L98 D-Port Corvette heads. Besides being a different shape, the d-ports are raised. I ended up welding the top of the primary tubes to the flange, so I'd have material to grind into. I used a LT1 exhaust manifold gasket (which match the L98 heads very well) as a template to mark where I needed to grind away metal to unblock the ports. I'll be able to let you know later this week how well it came out.

 

Good!! pics too if you can.

 

I'll take some pics for you. I finished the headers today. Now I just need to paint and install so I can make the rest of the exhaust. I'm going to do a 2.5" Y-pipe into 3.5".

 

ok kool! i would like to see how much was involved.

 

I'll get something posted in a few days. I've been real busy at work this week and have class till wednesday. I ordered a Flowmaster dual 2.5" into a single 3.5" y-pipe and a 3.5" oval Dynatech muffler today.

 

Ever get those pics?