Sometimes, the transmission is more central to the conversion than the engine.
We are occasionally asked why we don't have engine conversions to the lighter-duty Jeep transmissions like the T4, T5, SR4, Peugeot, and AX5. Simply answered; because adapting strong engines to weak components is a waste of the Jeep owner's time, energy and money. We won't make conversion kits to questionable transmissions. A light-duty transmission hardly belongs behind a stock Jeep power plant, let alone behind any source of substantial torque. It is our strong recommendation that you do a transmission conversion along with your engine swap when your Jeep has a weakling for a stock transmission. You'll be time, money, performance, drive ability and reliability ahead by doing so.
The first phrase uttered in many unsuccessful, problematic and expensive swaps is, "I've got this free engine from a buddy that I'd like to put in my Jeep." If the engine was free, there may be a few good reasons for it. Frankly speaking, if the engine is not a Chevrolet / GM V6 or V8, or a select few Ford or Mopar V8's, it is probably not going to be an enjoyable process. Engine preferences (and all the arguements and battles associated with them) aside - there are just a few motors that really offer a terrific chance of success and decades long durabiltity, parts affordability and sensible performance in a Jeep.
Some have asked us for conversions for foreign engines. While there are many excellent engines designed and built overseas, the installation and maintenance costs for these power plants and transmissions are costly and not always well suited to the high torque demands often placed on the Jeep drivetrain. Besides this, Jeeps are very American. They were produced to fight World War II and Americans have been in love with them ever since. In keeping with that spirit, we will continue to find and choose some of the best built and most well thought out conversions using the most appropriate components.
Though we are in the conversion business, we would urge many readers to not convert certain Jeeps. Over the past few years, there has been an unusual rise in the values of many Jeep vehicles built over the last several decades, and for good reason. Many collectors, most of whom were raised around these great Jeeps, have taken to preserving and restoring many of the models both simple and common, or great and rare.
As a rule of thumb, if you find that original WWII MB or Tuxedo Park CJ in your grandpa's barn or if you have an untouched Truck, Wagon or Universal, look into preserving it as one of the few originals, or take a good offer from someone who undoubtedly would. If you are looking for a champion rock crawler or a hunting buggy, look out for something whose collectability prospects are already diminished by modifications and wear. Many military vehicle preservationists and Jeep collectors will thank you for at least looking into it.