I am. I ran my exhaust just the like stock TPI with the F-body manifolds. I actually used a Magnaflow stainless Y pipe and modified it to work with the 4th gen manifolds.

 

 

I've got stock 2000 manifolds with stock 2000 cats on mine. But I'm running a BMR K member, I don't think the cats would of worked with the stock kmemeber. I cut the pipe on the cats and re clocked them so they fit. Which changed everything down stream. So I extended the pipe on the driver side so the flange was in a wider area. The y pipe is custom (and ugly) -- that is on my to redo list once I get everything else done (I'll probably take it to a muffler shop) tack welding exhaust laying under the car wasn't my idea of fun. I cobbled it together using pipe from the donor car and the thirdgen.

There are a few pictures in my build thread.
https://www.thirdgen.org/forums/ltx-...ter-years.html

 

I have a stock crossmember, and one of the Holley pans (actually equivalent, but it's essentially the same) and I am running between the oil pan and the crossmember, just like a stock TPI

 

 

 

I am running tubular k-member with factory 02 manifolds to a custom y-pipe

 

Sell yours, get the Holley pan, lol