'64 Chevy/'94 Formula Merge questions

[f4stunter]

I have a '64 C10 with a '68 stepside bed I got about 10 years ago when I was in high school. I rebuilt a 250 I6 mated to a turbo 350 tranny. For the life of me I can't remember why I quit the project. I know it was money related. I know it needed cosmetics and brake work & I figure I was young and felt like it was too much money and work. Back to present day, I'm pulling the truck out of the field in a couple of weeks and am contemplating putting the LT1 and 6-speed out of my Formula/Firebird. It also has the limited slip /w posi trac rear end I'm thinking about. I also read in another thread that people said the disc brakes off a late '80's model was too small. I can't see this being the case on my '94 as it has 16" wheels stock and fairly large discs but I'm wondering about that aswell. I'm up to the challenge just wondering if anyone has done any of this or part of it and what challenges they faced. Also if there are things that are bad ideas about the build let me know. thanks