Why spend more to get less? Your car already has a superior design installed.
You know better than I. No experience with either set up, but going with a street car motive, I want to have exhaust tailpipes over rear axle and exit behind rear wheels like the L-72 equipped mid sixties B-boy cars. The present set up interfers with that routing.
I have another G-Body I might buy and I may go a bit more radical with that one. I have 468" BB that needs to be employed!
Any other advice or observations appreciated as I had no idea these cars existed!