John, I'll give you two small pieces of advice to mull over with Barry. I went with the original iron block with the Edelbrock aluminum heads and Blue Thunder intake too. But my bore is only .025 over (4.155) and my stroke is only 4.125 -- all of this gives me a little bit of additional strength while allowing for easier higher revving (with a solid flat tappet cam of course). There is a tremendous fun-factor in revving a big FE past six grand and, truthfully, once you have horsepower in the upper 400's it really doesn't matter that much any more unless you are a serious racer. Talk with Barry about the long-term benefits of reducing your stroke a bit. He might tell you the benefit of reduced piston speed at high revs is a bunch of bologna.
The second piece of advice has to do with your rear end ratio. If you're going to go with the .64 fifth gear in the TKO you might want to seriously consider the 3.54 rear. I went with the 3.54 for a couple of reasons -- it made the speed relationship with the .64 gear "just right," it gave me the benefit of being able to go
slow in first gear without bucking, and it allows for softer take-offs while being easier on the clutch. So, all of that is just something to think about -- none of it is going to "make or break" your build....