Choosing and Prepping the New Engine

Ask most Jeep nuts (and other 4x4 types) about suggestions for engine swaps and the typical knee-jerk reaction is: "small-block Chevy!". I heard this a lot, and was all set to go with the 350 myself. Then I started looking for one. This popular engine proved amazingly hard to find, and the few sorry specimens I did come across were far from complete. In the course of my search, I did come across several 5.0L engines, however. And after getting some input from Larry Soo and several people on the JPOR list, the Mustang 5.0L began to look more and more interesting. Consider these points:

It's slightly smaller (in all three directions) than a 350
It runs cooler than the 350 (or so I'm told)
It's got an excellent sequential multi-point injection (SMPI, or SEFI) system, and good diagnostic access
The 302 has been in production for over 30 years, in applications ranging from passenger cars to light- and medium-duty trucks. Throughout its lifetime, the bellhousing bolt pattern remained the same, which means that the Mustang engine bolts right up to the old Ford truck 4-speed trannies, like the Ford T18, T19, and NP435!
Aftermarket support is not as good as for the 350, but if I need a water pump on a Saturday afternoon in Small-town BC, I can rest assured that the little Mom 'n Pop auto parts place down the street will have one for the 302.

After talking to some people in the US who had put 302s into CJs, it became clear that the best of the 5.0L engines were made between 1989 and 1993. These engines used Mass Airflow (MAF) sensors instead of the Manifold Absolute Pressure (MAP) systems used on the older models. Post-'93 engines are actually smaller, and have lower HP and torque ratings.

Some time later, I found a place called National Mustang in the local Buy & Sell. Fellow by the name of Craig runs the show there, sort of a one-man wrecking yard just for Mustang stuff. He sold me a 1990 engine that had 100000 kms on it, complete with everything I'd need to swap it into the Jeep. I got almost all the wiring from the donor car, the computer, the T5 bellhousing, clutch... everything. I'd highly recommend Craig to anyone in Southwestern BC looking for Mustang stuff - he had no problem warrantying the engine, and supplied me with several additional parts I needed later on, at no extra charge.

The engine was pretty grungy when I got it, so I decided to overhaul it and clean it up, both to learn something about how it worked (I'd never taken an engine apart before) and to get a feel for how healthy it was. I stripped it down to the block, leaving only the crank and pistons in place. The cylinder walls still showed the factory hone marks, proving that at least it hadn't been too badly abused. I cleaned the built-up carbon off the tops of the pistons, and started putting it all back together. Not having any training in engine repair or access to any experts in the area, I did not replace the rings or bearings, or have any shop work done on the engine. After all, I bought it knowing that it ran well and had good compression numbers.

So, back together it went! It was fun doing the reassembly. Sort of like a 3D jigsaw puzzle. Here's what I did:

Cleaned out the cylinders
New head gaskets (Fel-Pro)
New oilpan gasket (Fel-Pro)
New oil pump
New pushrods (the originals got mixed up)
New Cloyes double-roller timing chain
All-new Fel-Pro manifold, timing cover, water pump, and intake gaskets
Rebuilt water pump
New serpentine belt
New cap, rotor, plugs, and wires
Painted the block Ford Red

Here in BC, emissions laws require that all the emissions equipment from the donor vehicle be kept with the engine, so I left the 302's air pump and airflow valves and solenoids alone, as well as its vacuum distribution system and charcoal canister.

On to the next section, the Transmission and Clutch

Back to the Powertrain Swap page