[wanab5150]

Yesterday I was at a fellow Cobra owners house for the 4th. He has a 1600 serial numbered car (mine is 2769). His car also has a Roush 427R but his headers are different than mine in a BAD way!

Right off the flange about an inch is a weld where it appears a smaller port size tube is welded on. It is much smaller than mine and VERY RECTANGULAR. I stated mine also appeared somewhat squared, but I will recant, and after looking at his say that mine have dimples in the side to make room for the header bolts. The center tubes do not have the dimples like the outside tubes and mine only have one weld which is about 6 inches off the flange where the tubes are increased from about 1 5/8 inch to close to 1 7/8 inch.

Stephen at Full Throttle sent me some photos which clear things up. The photos are of both the 402's and the old 351 headers. If Superformance only made two different headers them mine are the "402" headers.

I would suggest anyone with a Superformance check to see what they have. After seeing how tiny the old 351 headers are it's ridiculous to use them with a big inch motor.....almost as bad as using the stock 2" mufflers.

If you have the old headers and don't swap them for the bigger ones, it WOULD NOT benefit you to got to a larger muffler because it is completely choked by the exhaust port/header anyway. You would need to swap the entire system for a real HP gain

So...basically if you look at your headers and they have a weld out 1 inch from the flange and another 5 inches out, and the tubes are rectangular at the flange, then you have headers for a stock port 351 head.

If anyone wants photos of the two different headers drop me an email and I'll send them to you. Meantime, I will be waiting for the 3" mufflers and report back with the results.