A couple of things you will have to modify.
1. Brakes. Get an aftermarket firewall-hung brake conversion kit. Probably run you a couple hundred bucks from Speedway if you go with manual. Power brakes will be about twice as much. There is no room for the lever arm on the stock brakes. Hits the exhaust on #7 on mine. You CAN modify the stock brakes in a pinch, temporarily, by trimming off the top of the lever arm, depending on what kind of exhaust you do.
2. Steering box. This is an infamous one. Even with my upside-down shorty headers, I still had to move my steering box a good inch outboard using spacers and longer bolts. It did change my steering wheel alignment too.
3. You'll need a crossmember. I suggest a bolt-in tubular crossmember from Speedway Motors. Do NOT!!! weld it in. If you do, you won't have enough room to slide the engine back. It's a very narrow engine bay.
