I did the Ford this summer and it was easy. Never did the Chevy so don't know how easy it is but I'm told it's easy too. Think the Chevy requires some grinding here and there to work. I know for sure the big Bronco stuff is direct bolt on.
I reused my stock 74 locking hubs, H-block and durn/drum M/C. I already had the stock power booster and bracket hooked up with my drum/drum setup.
As for cost, I would have to price out the parts needed at the local parts store or form one of the venders and see which was cheaper.
Tim