Specifications

F. Fuel System: The existing fuel system has two metal lines that come from the gas tank up the driver's side of the vehicle.
One goes to the fuel pump and the second goes into the smog system. The fuel system line will need to be rerouted across to the
passenger side of the engine compartment to couple to the Chevy V8 fuel pump. The vent line will be installed into the charcoal
cannister.
1997-05 JEEP WRANGLERS (Gen III V8):
The information that follows is base on Vortec engines that we sell. A Vortec engine obtained elsewhere may have some
differences. The Jeep TJ should have at least 1” of body lift before starting and a minimum of 4” suspension lift with adjustable
bump stops. The suspension lift is mandatory to clearance the A/C compressor.
Motor Mount: These mounts require the original motor mounts from the frame to be removed. Also remove the steering pillow
block bracket and discard. The frame surface for the mounts should be bare metal so that there are no contaminants in the weld
area for the new mounts. The TJ frame has a small hole on both sides that originally held the brake lines. We use these holes
for the alignment of our mounts. Clamp the mounts in place and verify that the steering pillow block fits to our mount without any
interference. When the mounts have been correctly positioned, weld them in place and paint. The Vortec engine is very large.
Firewall modifications are minor, yet mandatory. The engine and transmission should be bolted together for an easier installation.
Air Conditioning Modifications: In order to retain air conditioning into the TJ, there are some fairly major modifications that
need to be made. The frame must be modified if the air conditioning compressor is to be used. The configuration of the
serpentine belt on the newer blocks will not allow the compressor bracket to be located anywhere else besides stock. The best
way to determine the proper clearance on the frame would be to do a dry run once the new mounts are in place. It is a good idea
to keep the stock A/C pump lines and manifold handy when checking the clearances. Please keep in mind that it is far easier to
check often and do minor trimming than it is to repair a frame rail with too much taken out of it. When you feel comfortable with the
notch in the frame, a piece of scab plate MUST be fit and welded into place on the frame to secure the frame integrity.
Vacuum Connection for Brake Booster: You will notice that the Vortec block has no provision for a vacuum line for the brake
booster. There is a small port on the back of the intake manifold that can be used.
Gauge Wiring: The Vortec V8 and the Jeep systems do not “speak the same language”. In our installations, we retained the
stock Jeep computer as well as install the new Vortec computer. We retained the stock Jeep sending units and attached them to
the GM block (oil pressure, temperature, and fuel level). All of them work fine except the tachometer. An aftermarket tachometer
would be the easiest option at this point. Since you are using the stock sending units, the Jeep computer thinks that the original
engine is still sending information.
Radiator Hoses: For our conversion we ran to our local auto parts store for hoses. The lower hose is NAPA P/N 7473. The upper
hose is actually two separate hoses spliced together. A 1/2” hole with pipe thread was tapped into this splice for the stock TJ
temperature sending unit. The two hoses were NAPA P/N 8111 and 8563. We used our custom Rad-a-Kool radiator for this
conversion to make sure cooling would not be an issue. The radiator fit into the stock location on the Jeep TJ. The Vortec engines
recommend a 50/50 mixture of Dex-cool and water.
Throttle Linkage: The throttle cable that comes with our Vortec engines will work with the
TJ pedal. To connect the two, start by drilling a hole in the firewall where the stock Jeep cable
was located. The hole diameter is determined by taking a pair of calipers and measuring the
mounting slot on the stock GM throttle linkage. Use the correct drill bit and open the stock
hole on the Jeep firewall. The hole must be big enough to accept the housing, but not too
large for it to slip through. The inner cable may need some shortening to work correctly with
the stock pedal. It may even be necessary to solder and relocate the stop on the cable.
Fans: Either a stock clutch fan or an electric fan will work with these motor mounts. With our
aluminum radiator, there should be approximately 2-1/2” between the clutch on the fan and
the radiator fins. A custom shroud will have to be fabricated if you use the clutch fan. An electric fan is what we used and it works
great with these mounts. There is ample clearance in the engine compartment which allows for good air circulation. We offer a
Spal fan and mounting brackets to fit our radiator under Part No. 716670. This fan is rated at 2360 CFM.
Exhaust: All of the stock exhaust system must be removed for the Vortec conversion. New pipe should be run from the manifolds
all the way out. Routing the exhaust around the frame should not be a problem. Weld flanges and crush gaskets are available
separately for the truck-style Vortec manifolds (AA P/N 716573 and P/N 717514). If you are doing a smog legal conversion, you may
need to find a stock GM vehicle to measure the location of where the oxygen sensors and cats are located on the stock pipes.
Intake: The intake we used on our TJ installation was a GM 25176891. This ducting was cut and modified to fit the Jeep
configuration. We used a K&N air filter, P/N E-1796. This setup required a electric fan to be used.
Fuel System: Refer to the fuel section of your Jeep owner’s manual before servicing or taking apart any piece of the fuel system.
Special fittings, pressurized line, and certain procedures must be taken into consideration before work can be done on the fuel
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conversion application summary (1987 & newer)