I made a custom crossmember out of 2x4 3/16" steel and mounted it to the bottom of the frame. I will be changing this to 2x4 c-channel though to raise it up beacuse it sits too low for my liking. It is very close to where the stock crossmember sat..i think its a little further back but ill check this weekend.
I also had to make a new transmission hump..It didnt have to be this large but i wanted to be able to put the transmission straight up and straight in to the back of the engine without any fooling around.

And lastly I had to get the gm master cylinder adapted to the dodge nylon tubing and slave cyinder and make a custom slave pushrod to get the clutch travel right
I used a 12 valve non intercooled from a 91 Dodge. It works very well