I'm getting ready to buy a set of Mac Headers with ORY for my 98 Z28 A4, and I was just wondering if there is any common problems after installation of headers. After the installation does the car have to be tuned or anything along those lines. Any help is appreciated.

 

It does not have to be tuned, but you will get more hp from them if you do tune the car.

 

A tune may help slightly after the install. I'd let the car try to "adjust" itself first before tuning so that you have a good baseline. I would also do the collector mod and grind down any rough welds before the install. Both headers will go in from the top if you remove the passenger-side valve cover. I re-used the factory gaskets and bolts (less than 10k mi at the time), but have heard good things about the Stage 8 bolts. Good luck and I think you'll like the performance for the price.

 

What he said

I had MAC on my lt1 car, so I can give you my experience on that end.
I ground down the welds inside the primaries because they were a bit obstructive.
They went in pretty good. Plug access was great after the install.
Of course I pulled the emissions equipment out at the same time.

Like I said, it may not apply much to the ls1 plant, just offering my 2 pennies