I debated this issue back and forth, headers and kit v. stock ram horns with a custom build.
What it came down to for me was concerns about not being able to get my car worked on without the cats. I'm getting more confident working on my car though I'll never be able to do the work a lot of these guys do. I needed to be able to take my car in when I thought I would be getting in over my head. Even though your state or area does not inspect, the Feds require the emissions equipment to be on the car. The better shops in my area would not work on the car without the cats for fear of a $10,000 EPA fine.
I was also concerned about the bends in the "generic" kit not matching. While the companies do a good job, every car is a little different and I didn't have the equipment to make them fit. I heard lots of stories about the tight fit and rattling from under the car.
As I recall the pricing, the kits were $300 - 350 or more by the time you got them delivered, another $150 or so for a pair of delivered mufflers and the cost of the headers. I didn't look to closely at this but vaguely recall they were $200 or so.
I had my whole installation done for $700 with a good warranty. This included two FM Delta 50's, two high flow cats and the 2 1/4" piping that was recomended for the low HP 77's. Sounds great (my link is above, take a look as it shows the config and the sound with the new system).
Others have posted HP increases when they changed over, I personally didn't see it. I may have already had a free flow cat the way the thing was rotted out.
I will evewntually modify the engine for more HP and get the headers and have the pipes cut/bent to fit them but other posts suggested that the ram horns were good enough on the 77.
Good luck with your decision.
Bob
