Gotta add my .02 cents here. I was in the same situation. Had a tired, old, very, very leaky 2f. Liked the way it ran as far as reliability, quiet, etc. But, I really did want more power, not just for off roading sake, but for my own drive-ability sake in terms of being able to run at freeway speeds, pulling hills, pulling a trailer, pulling a trailer up a hill, pulling a trailer up a hill with 33's and heavy bumpers and winch, and camping gear, actually being able to use 4 Hi for a change, the list goes on. These concerns really added up to
my personal need for a V8. Therefore, I went with a V8 but opted for the Mark's adapter and kept the stock 4 speed (unfair advantage here since I already had a Farey Overdrive therefore the Mark's kit was a no brainer). So far I love it and have no regrets and would do it all over again. Easy conversion, adapater kit really made it quick and easy, some minor mod's, but nothing major needed to make it all work. In the long run, maybe someday I'll regret it when I'm old and grumpy, but for now it meets my personal needs and suits my lifestyle well. Personally, I think it all comes down to what you want and expect from your cruiser. Once you really figure that out, then the choice will be easy. And gas mileage? What gas mileage? Gas mileage never evened factored into the question, I mean lets face it, these things were never built for gas mileage purposes. If you can get better gas mileage great, but really who cares in the long run. If your vehicle can't get you where you want to go painlessly, what good does a few extra miles to the gallon do? Good luck.
