I plan on going to a 1990's chevy TBI and computer later on.
Have any of you guys done a Vortec to stock TBI?
I'm replacing my 5.7 TBI with a Vortec short-block.
I can't help with most of your questions--but--you'll need to think about what fan/water pump/ps/alternator/AC belt system you're going to use.
If you use the '67 V-belt system, you'll need the '67 water pump, fan clutch, and fan. The stock serpentine system spins the water pump, fan and clutch backwards, AND the Vortec water pump and Vortec block don't have provisions for the coolant bypass required with the older V-belt, or TBI-era serpentine system water pump.
Depending on what you use for a drive belt system, you may need to drill the bypass hole in the front of the block. Some Vortec blocks have the hole partially-drilled, some blocks have the hole not there at all. I have one of each style of block, and I'm drilling the bypass hole in both so I can use a bypass-style water pump.
The Vortec intake manifold has a coolant bypass instead of the water pump. Unless you use the Vortec intake manifold and special thermostat, you'd need to use an older water pump and drill the block.
You'll also want to be sure to use a timing cover/timing pointer and torsional damper that go together. They're not all calibrated the same. Make sure you find TRUE TDC on #1, and that the damper and timing pointer line-up at "0". If the timing marks are straight up-and-down, you'll need to avoid the "short" water pump because there's no room to shine the timing light between the back of the water pump and the front of the block. Short water pumps require the timing pointer to be offset to the driver's side of the engine--which means the torsional damper has to have the TDC mark offset to the driver's side to match the pointer.
The Vortec blocks have two fewer bolts that hold the timing cover in place. I'm drilling and tapping the extra holes in my blocks so I can use any SBC timing cover, not just the plastic, disposable Vortec cover.