There are lots of engines available to stuff in your 4x4, but the small-block Chevy has never been surpassed as the hottest engine swap ever. With the Generation III and IV engines (aka LS Series) flooding the used and crate engine market, they are quickly replacing the old standby small-block GM as the easy engine to swap due to their ability to produce cheap, reliable, fuel-injected power.
We did a buildup on an LS-style engine in Aug. '08 ("Lego Engines"), and now it's time to stuff one under the hood of a truck. The old Dodge M37 military truck you see here is one of the next wheeling rigs we'll be building. There will be more info on it in the future, but for now we'll just touch on things to remember when swapping any engine in your 4x4. (Oh, and before you Dodge guys get all bent out of shape over our putting a GM in a Dodge, let us tell you that we saved this truck from the crusher; it had no engine when we found it and the used GMC 6.0L V-8 was a deal we couldn't pass up.)
Note the front differential at full suspension compression, as well as driveshaft, steering, exhaust, transmission and transfer case clearance, the fan-to-radiator spacing, and the ability to get to the engine for any maintenance. Offsetting the engine an inch or two for clearance and angling the back down a few degrees (we went to 4 degrees) isn't uncommon. We swapped out the standard truck exhaust manifolds for these tighter-fitting F-body manifolds and are using the rear sump truck oil pan.
A V-8 in a Jeep?!
Folks have been putting V-8s in Jeeps and Toyotas for ages, and Advance Adapters has been there every step of the way. We went to Advance for the bellhousing, clutch, and flywheel for our Gen III engine in our old Dodge project, but the company also offers a full line of parts to stuff almost any era of GM V-8 into a CJ, Wrangler, or Land Cruiser, such as motor mounts, exhaust headers, and adapters. We wouldn't be surprised if Advance also has a kit for the Gen III and IV V-8s in a new JK Wrangler before too long.