Yeah, I've read the thread last year.. but was unable to get clear picture on how to do it, I roughly know how to do it.

*****, make sure you take some pictures of the header after the mod before you fit it back to the car...

 

Here’s the follow-up thread for willy69 https://www.northamericanmotoring.co...ad.php?t=62142 .

My pre-cat delete version modified at Corky Bell’s shop.


The pre-cat has a narrow opening (less than 2 in. ID); keep in mind only one gas pulse at a time passes through here so that’s not so bad, and the stock head and SC pulley don’t provide much for port velocity, so any thing to help speed things along like this swage shape, is a good thing.


However, the cat core is tightly spun which may cause some restriction when VE is improved upon. The aftermarket cat on the left is 300 cell; the OEM pre-cat appears to be much denser.


In addition to replacing the pre-cat with open tube, the flange ports were enlarged to match my ported head, an additional O2 ring installed, the wire feed weld bead at the exit was ground down (almost .25 inch ID gained), weld blobs were removed at the flex joint, and the primaries were ceramic coated.




To handle the increased noise, a 5 inch diameter Magnaflow muffler is attached to my one-ball exhaust.

 

nicely done.

 

Very nice job for people who don't want to spend extra $$$$$ on a new header.

 

This is exactly what my stock header looks like. Nice job Keith, and thanks for the post.

 

wouldn't expect anything less. Next thing you know though, you'll be running longer primaries and you have...

a header again!!!!!

Matt

 

Thats funny because I was thinking the same thing - cut slightly higher, extend pipes, ect......................................

 

Pretty spiffy. I knew there was a reason I kept the pieces of my stocker (one of the seams on the pre-cat split - the parts are in two pieces).

 

nice fabrication

 

I bought a stock header from a local guy who had already gutted the pre-cat and the cat. Probably gonna put my cat on it though so it doesn't sound so raspy and loud. However, the guy also went to the trouble of porting it out for more flow.


Cost me $60