That depends on the flavor of 2004r you choose. The stock ones from a GNX are quite a bit stronger than, say, a Buick LeSabre.
The driveshaft is the same length as the powerglide and TH350. You'll need to modify the crossmember.
You can see the modified crossmember I'll be using here:
I also had to get new linkage, a TV cable, and, of course, a new bezel. If you have a floor shifter you might need to do more.
For wiring you'll need a keyed power source and a new switch or relay for the brake light to disengage OD. I haven't gotten that far yet.
May also need a new dipstick or modify the old. Mine, luckily, already has a correct one.
You can see the body isn't huge. Mine is built for 700hp. I think it'll hold up just fine...
