I have a Mike Leech/Mopar header on my 90. First time they sent it to me, it did not have the EGR fitting. I called up Kolak, and he said just send it back to Mike Leech, he'll put it on and send it back. I said, I thought the Renix and HO manifolds were different. Nope, the only difference is the EGR. I don't know what the latest year this is true for, but I can tell you for a fact that the HO header from Mopar fits just fine on a Renix. I can't speak for the rest of the exhaust system, since all of mine is custom.
Fred