Right now I'm roughing in a set of Pro Parts RB A-Body headers. Keep in mind that these are the "old" ones, I bought an unused set on ebay because I had heard how well they fit.

I was a little apprehensive, because once you cut the fenderwells there's no turning back.

I assembled them on a bare 440 on an engine stand first, and everything went together with little headache. Just be sure to take a small grinding bit to deburr the edges of the pipes and and clean the welding slag out of the collectors, or they won't go on very well.

I carefully cut out the fenderwells exactly as directed, and installed the empty 440 in the car...and the headers wouldn't come close to going in. I had to fit and trim several times, and in order to get them in and out without scraping everything up when they're coated, I had a much larger hole on each side than the templates showed.

Passenger side still needs trimmed closer to the firewall...


Drivers side also. It's almost as if the firewall edge on the templates were too far forward...


The driver's side will need "adjusted" to keep from hitting the shock tower...


The driver's side hits the bolt on the steering column with every turn of the wheel...


The passenger side problems are under the car. The collector hits the crossmember...


Which causes the collector to stop short of going onto the pipes as far as they should...
(sharpie marks show where they assembled on the stand)


And the tabs on the collectors should be on the outside tubes of the headers,
not here...where they will interfere with the transmission clearance.


The car has Schumacher A to B/RB swap mounts in it. The engine is level in the car. Raising it about 3/8" would help the driver's side problems, but would exaggerate the clearance problem of the collector on the passenger side. I'm thinking about taking the passenger side collector to an exhaust shop and having about 1-1/2 inch extensions added to each of the four tube receivers, and just beating the livin' crap out of the driver's side where the interference is.

All in all...after working a day and a half on getting them installed and still needing more modification....I just shut off the heat in the garage and came inside. Screw it...I'll get back to work on it once my blood pressure goes down a bit.

Any suggestions??