According to Snider, the big problem with a V-8 swap into a YJ is that the stock five-speed transmissions tend to explode under torque. The '87-'90 manuals are especially prone to fail, so it's best to swap engines and trannies at the same time. GM V-8s with TH350s or TH700-R4s (or 4L60Es) are particularly popular. Companies such as Advance Adapters offer the needed swap parts. The AMC V-8 engine family, which is a bolt-in replacement for the 258 in CJs or YJs, isn't so easily adaptable to the 4.0L YJ and swap parts are not readily available. Shown here is Ron Esch's 300-horse injected Chevy 350 with a 4L-60 tranny and NP242 transfer case installed by Stage West.