Motor and Drivetrain!

Oct. 01, 2005 By Jim Weed

500 ci Cadillac
The goal for the motor was to maintain reliability while maximizing torque. A 1976 500ci Fuel Injected Cadillac motor was chosen. This required custom motor mounts but minimal wiring changes. I am extremely pleased with the four wheeling attitude of this motor. The original Scout II power steering hoses bolted up to the Cadillac pump. The original Scout II alternator is GM so the Cadillac alternator worked fine. The factory power brake system was converted to a hydroboost system. You can see the ARB air compressor mounted to the front shock hoop. A new 500ci Cadillac radiator was purchased and installed. Note the relocated heater box (inside the Scout) and the heater hoses coming off it.


Ready for Installation



Because of the low gear ratios in the axles an overdrive transmission was considered a must. The NV4500 Chrysler 5-speed was picked because of the transmissions combination of a granny low (6.34:1)and an overdrive (.74:1) in one box. Adapters were required between the engine and transmission as well as between the transmission and transfer case. JB Conversions (318-625-2379) supplied the transmission and transfer case adapter plates. The transfer case is a Dana 300 utilizing the more common Jeep style mount vs. the rare 1980 Scout II style mount.You can see the 500 ci Cadillac motor bolted up to the NV4500 transmission in this picture. If you look real close you will notice a 2nd 3/8" adapter plate between the bell housing and the motor. The closest bell housing I could get from JB Conversions was for a Chevolet motor. Cadillac, Buick, and Olds use a different bolt pattern then the Chevy motors. Hence the addition of the 2nd 3/8" adapter plate between the bell housing and the motor. This adapter was designed by Jim Maulis


Low Range Crawl Ratios
Off-Road Ratio's R & P Dana 300
NV4500 1st 6.34 4.88 80.8:1
2nd 3.44 4.88 43.8:1
3rd 1.71 4.88 21.8:1
4th 1.00 4.88 12.7:1
5th .73 4.88 9.3:1

Rear Dana 60.
Sierra Trek!








The original Dana 44 front axle was twisted at both knuckles to increase the caster (improving the drivability) and decrease the angle on the front drive shaft. The front differential is a Detroit Locker with 4.88 gears. The power steering pump was boosted to compensate for the front locker. The rear axle is a narrowed Dana 60 with semi-floating (single bearing) 1 1/2" diameter 35 spline Strange axles. This allowed me to use the factory 5 on 5 1/2" wheel pattern. The rear differential is an air locker with 4.88 gears. The rear brakes were replaced with disk brakes and rotors from a Scout II front axle. A custom rear aluminum differential cover was added to complete the rear axle assembly. Vent hoses were added to both axles for those occasional deep water crossings. The rear drive shaft utilizes a CV joint. Newsletter
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