First, alot depends on the smog regulations of your state. That would be the first thing you need to know. Second, most of the "vacuum" lines in your engine compartment have nothing to do with Smog. Your 302 should have a Cat, Smog Pump, and EGR valve. Aside from the few lines that go with them, that's it. If your 90 302 is anything like my 88 302, you can't even see the hoses for the EGR, it runs behind the block to your cat. The only thing that I could see that "get in the way" would be the hoses off of your Smog pump, but even that is disputable. You could remove your cat and Smog pump as long as there are no emission checks in your state, but even that is debatable on how thorough your inspectors (if you have to get it inspected) are. Plus it can effect performance (not saying it will, but it may).
As for the CJ-7, if I remember correctly the CJ line stopped production in 82 or 84, so most CJ-7's and CJ-5's were made before most emission regulations and what emission stuff they may have, most likely isn't checked because of their age.
Lastly, the kits you refer to for the CJ-7, I"m not familiar with, but if they remove most of the "vacuum lines" I would have to assume it has nothing to do with emissions, and more with removing actual vacuum lines. Also, most (if not all, not real familiar with Heeps) CJ-7's and CJ-5's are carbureted, your 90 302 Ford Bronco is EFI, so all the clutter in your engine compartment serves important purposes, telling your computer every little detail of your engine so it runs as (supposedly) efficiently as possible. But that discussison is more for FIREGUY50 to respond, not me.
