Specifications

1997-2005 JEEP TJ WRANGLERS:
Engine conversions in these years, replacing the 4 cylinder and in-line 6 cylinder engines, are
becoming very popular. We have a complete line of bellhousing adapters to use any one of the
original stock transmissions. We also offer a full complement of transfer case adapters, adapting
to many of the Ford & Chevy transmissions.
A. Stock Manual Transmissions: The information listed on the previous page is the same
as for the TJs.
B. Stock Automatic Transmissions: The information listed on the previous page is also the same as for the TJs. The only
exception is the 2003 Jeep TJ 6 cyl. and 4 cyl. These vehicles switched to a new style automatic transmission. We currently do not
offer any adapters for these transmissions.
C. Optional Transmissions: We offer numerous types of transmission options that could be substituted for the original Jeep
transmission. The options for the Chevy conversions would be the GM automatics such as the TH350, TH400, 700R-4, and 4L60E;
and for the manual transmissions, the NP435, T176, T18, SM465, SM420, and NV4500. The transfer case equipped in these vehicles
is manufactured by New Process Gear, and came equipped with 21 or 23 spline input. For more information, refer to the Transfer
Case section of this manual.
D. Exhaust: We offer a header system for a Chevy V8 into the Jeep TJ. Part No. 717090 headers are a rear drop exhaust that
stays inside the frame rails. If stock manifolds are required for emissions, car manifolds work the best. On Dodge engine
conversions, we used the manifolds off of a Dodge 1500 series pickup. We do not offer any headers for the Dodge blocks.
E. Radiators: Both the Chevy and Dodge engine require a radiator upgrade. We offer a copper/brass or aluminum radiator that
fit the TJs. Both radiators mount in the stock location and work well for cooling the new engines.
F. Driveshafts: On Chevy V8 installations retaining the stock transmission, the original driveshafts should not require
modifications. When upgrading the transmission, driveline modifications should be expected. Driveshaft modifications on the
Dodge conversions will depend on the transmission that is going to be used.
G. Engine Location: The mounts designed for the TJ set the block in the ideal location in the frame rails. The mounts were
created to allow both the GM and Dodge V8s to be installed with both stock and aftermarket suspensions. The GM V8 mounts
replacing the 4 cylinder is a bolt-in motor mount. The mounts for the GM V8 replacing the 6 cylinder are a weld-in. Welding is also
required when installing the Dodge V8 engines. All mounts allow for some fine tuning of engine placement; front to rear and side-
to-side.
1997-2005 Dodge Engine Swap:
The 5.2L and 5.9L Magnum gasoline engines have good dependability ratings and are wired similar to the Jeep power plants. The
best donor vehicles are 1996 & newer Ram 1500 – 3500 trucks, Dakota and Durango trucks. Be sure, as we did, to get all wiring
from the donor truck. If your auto dismantler will not unplug the connectors for you, please offer to do it yourself. You will need many
of the plugs and wiring from the donor truck. Hacked and cut wires are difficult to trace because the factory service manuals reference
the plugs in the schematics. The emissions equipment, such as the charcoal canister and leak detection pump are important to
the computer when performing pre-startup diagnostics. Get all these parts now because if you have to buy them later you will spend
a lot of dollars from the dealership - whereas the auto recycler may just “throw in” the parts you need.
The stock “Y” pipe is also a good starting point to help route the exhaust. Catalytic converters are also expensive aftermarket pieces,
so get them too. If you are using a manual transmission, use a donor engine and ECM that was originally manual. Do not try to
attempt to run the electronic overdrive transmission from the manual computer. It is more trouble than it’s worth.
We have found that removing the grille and fenders makes the conversion go much faster. The factory motor mounts must be
removed to install the new weld-in mounts. Use a grinder to trim the mounts from the frame and upper control arm mount. Take
care not to damage the suspension mount point. The V8 mount position is determined by a pre-existing dowel hole in the frame.
Remove the large factory rubber mounts from the V8 (commonly found in Dodge truck
applications) because they will not be used. Advance Adapters P/N 713094 is used for
this application. The frame mounts are easily placed in the engine bay and welded. Be
sure to have a qualified welder do this because the welds will be supporting about 500
lbs. Cleanup and painting should be done prior to lowering the V8 into the chassis. The
rubber bushings will index into the upper mount and be secured with the 5/8” bolts into
the lower mount. Reinstall the skid plate. While still on the hoist, trial fit the drivetrain
assembly. Look at possible interferences with anything in the engine bay. It is best to install
the transfer case now. Attach the linkage at the case. Adjustments and/or modifications
may be necessary for the movement of the transfer case. Bracket P/N 715542 may be
needed if using the NP231J.
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conversion application summary (1987 & newer)