The Chevy 200, 229 CID and 4.3L V6 are outstanding motors. These engines are essentially a truncated Chevy V8. They make for great Jeep engines. Like the Small Block V8, the 4.3 features excellent advancements through its production span. This motor is being put into Jeeps with frequency due to its size, power, economy and weight. Modern incarnations include the Vortec V6's, which offer unusal torque for a V6 and a neat powertrain control system, in the vein of modern GM powerplants.
The Vortec V6, while short enough to fit into early "low-hood" Jeeps, is too tall for proper fit unless one is willing to do a 3/4" to 1" body lift and possibly modify the 4.3L air intake arrangement. Alternatively for these CJ2, CJ3 and M38 Jeeps, we recommend earlier versions of the Chevy V8, Chevy V6, the Buick V6 or the Ford I4.
The 1955-2001 Chevy Generation I & II Small Block V8's are very popular for Jeep swaps. Stock Small Block series engines consist of the following displacements: 265, 283, 305, 307, 327, 350, 400. Some of the reasons for the popularity of these engines are: availability, outstanding parts interchangeability, compactness and light weight, plus the fact that these engines fit nicely in most Jeeps. These engines have been popular choices since the mid-sixties, and because they are so familiar, the information and parts required to swap them are more widely available than with any other motor.
The Generation III+ engines are creeping quickly up on the classic Small Block in popularity. However, the Chevy V8 is essentially immortal in reputation and implementation.
The rise in poularity of the GM Generation III+ Small Block V8's has been meteoric. They feature tremendous power, efficiency, clean-burning, and well supported computer and wiring systems. Like their Small Block predecessors, the Gen. III+ family features availability, outstanding parts interchangeability, compactness and light weight, plus the fact that these engines fit nicely in most Jeeps. We expect them to surpass the Chevrolet Small Block in frequency of conversion before the end of this decade.
Chevrolet Big Block V8 engines are fantastic engines, but best relegated to wide-frame Jeeps like the FSJ and YJ. With the Small Block V8 and Gen. III+ motors developing such adequate power, having lighter weights and more compact envelopes, one should reallly only choose a Big Block for severe service and ground-splitting power.
The Chevrolet I6 engine made from 1962-1990, in displacements of 194 - 292 CID, is an installation possibility into many "long hood" Jeeps, including the CJ series, J Series, FSJ, M715/725 and YJ. They are good, solid motors. Individuals researching their installation should know that they have the same block / bellhousing pattern as the Small Block V8 series and therefore share the same transmission compatibilities as listed elsewhere on the Novak website. These engines were also GM equipped with angled engine mounting brackets that emulate the factory Small / Big Block V8 mounting bosses.
As these are longer motors, they do not install well into early CJ Jeeps. Also, the installer should consider that these engines do not generally enjoy the fuel economy or powerband as similarly displaced Chev V8 motors like the 283 through 327 Small Blocks.