Which K frame would you use, given the choice?

To answer all the questions.... I have 3 cars:

1) 1971 340 4 speed. Complete numbers matching Hammtrack-built car but quite rotted;

2) 1970 340 4 speed. LA-built rolling chassis. California car. Solid car apart from lower quarters, trunk pan and left inner fender battery damage. Original K frame with Kelsey Hayes discs;

3) 1970 340 4 speed. Windsor-built rolling chassis. Came into my possession with 73+ K frame with slider front discs and 8.25 rear installed.

My goal is to take the best of all three cars and make one excellent vehicle. I'm just wondering is either K-frame design is fundamentally superior to the other. Shy of grafting the VIN stampings from the complete car onto one of the rollers (likely the Cali car) this will not be a numbers matching car, and I'm totally cool with that. I'm building this for the missus and myself and not the purists.

It may be sacrilege, but I plan to shelf the thermoquad in favour of EFI.

I'd keep #2 as is and work from there, nothing wrong with Kelsey Hayes discs, and I'm sure it has an 8 3/4 rear to boot. Just get everything up to snuff. Spend your time and money elsewhere. Same for the EFI. But it is your car, time, and money. Good luck.