I also have a 78 CJ7....and the RE 4.5" lift.
I installed it about 6 months ago. (only been driven on a few times and wheeled once)
Some things to possibly expect:
-Kit was missing greasable zirks, 5 of them to be exact.
-Sent me the instructions for a TJ lift which sent me spinning circles for a good hour and a half trying to find the missing parts and non-existing parts on my Jeep.
-The shocks they recommend for the kit are not the right size. They are extremely limiting. I would tell you the amount of play you need in yours but I do not know where my numbers are. I ended up sending back the shocks that they said go with the kit and getting the right ones.
-The ride is extremely stiff. I did my research before buying it and everyone said it was one of the softest ones you could get with the best flex. (It is possible that mine is not broken in yet though!)
-The steel braided brake lines are great, although possibly a little too short. (no issues yet)
-Some misc. parts just plain do not fit. You can tell that half the stuff is just universal. So a little modification and give and take has to be done.
-Good part, I got 5.25" out of the lift....for now.
-The springs seem really meaty!
-Even after all that, I think it is still worth it. But it was a difficult install with all the problems I ran into. And my dad owns a full blown automotive shop with 6 lifts. So all my tools are snap-on, computers, air tools, etc. It still took us about 6 hours to fully install.
Hope I didn't ruin it for ya. Just letting ya know. You prob. won't have as bad of luck as I did. BUT CHECK THE SHOCKS!!!