Just a few questions:
- What exactly is a "cold air maf"? Do you mean a cold air intake, or an aftermarket mass air flow assembly, or both?
- How big is the MAF housing you have?
- Why 25 lb./hr. injectors, and is the MAF you have calibrated for them or do you have a tune?
- Have you purchased a throttle body yet?
The moral of the story is you need the spacer bore to match the throttle body size, and you should port the upper intake inlet to match the spacer.
Eh, I'm not sure here. The opening on a tubular GT40 intake may be 70mm, and I'm not sure about the '93 Cobra upper, but I know for a fact the opening on an Explorer GT40 intake is definitely not 70mm. It's closer to 65mm.
Again, the moral of the story is everything needs to match. It's okay for the MAF housing to be a bit bigger as it should be (1-6mm is good, maybe even 10mm bigger), but the throttle body, spacer (or elbow for 94-95 applications), and upper intake inlet really should be the same size. Any steps here will cause turbulence.