This is a question for the most experienced off-roaders out there. Those of you with lots of experience with different vehicles, engines and off-road situations. In your experience what engine has served you best? Let us know!  

It's pretty hard to beat the good ol' Chevy small-block. That's probably the most common engine swap I've ever seen. A lot of guys say diesels make good off-road engines, and I agree, but the weight and cost of them keep them from being really popular. Not to mention the fact there are very few small diesels out there that would work in Jeeps and other vehicles like that. Most of them are the big hoss engines like the Cummins, Power Stroke and Duramax.  

I think the 304 or 401 AMC motor is the best and it is still a jeep not chevy beleive  me I have nothing aginst chevys I just think if you are driving a jeep have a orignal jeep motor I have two 1989 yj and they both have 304 in them Nad I converted them my self My next project is a 1977 El-Camino and right know Im building a 401 from the ground up I will get pitchers and add them to my profile later on  

Okay, I'll give props for the original AMC V8. It used to be you couldn't find any performance parts for them, but there's getting to be a pretty decent aftermarket following for them now. I know I talked to a guy from Edelbrock that said they've gotten a lot of demand for AMC parts. A built 401 in an old CJ would be pretty sweet, I've got to admit.  

depends on the type of wheeling yer gonna be doing...
I prefer gm 6.5td in the cj and the fullsize for trail and crawling, for all out mud bogging a high strung sbc or bbc is the way...

the amc has always been a headache for me, Id rather have a 4.0  

Cummins diesel.No fluctuating fuel problems.better torque (better for controling a climb).A lot of jeep owners are starting to cetch on with the 4 b series Cummins.Ive got a lot of guys on the diesel ban wagon down here.  

Yeah, starting to see a lot of 4BT swaps into older Jeeps and Broncos. They're still a little on the heavy side, but good engines.  

I have to vote for a fuel-injected Chevy small block.  The Gen III V8s have a lot of aftermarket support and are very popular.  The L98 tuned port V8 was a very good performer, especially in low-end torque delivered.  The tried-and-true Chevrolet throttle body V8 is still the easiest engine to swap into a Jeep.  All this being said, the Hemi 5.7 MPI crate motor we used in Project Old School YJ (you'll see it soon) is a very strong runner, although not as easy to install as a Chevy V8.  

with all of the great experiences I've had in my 2001 TJ i'm inclined to say it's the 4.0L I-6. I know I'm gonna hear it on this though but man has it been a great engine when mated with correct gear ratio and tire size.