90 GMC Jimmy General Maint & Upgrades

[chappys4life]

Recently inherited my step dads 1990 GMC Jimmy. Its a amazing vehicle and was his daily driver but its sitting around 300k miles (odometer broke at 267k) and it needs some maintenance. Right now fighting a check engine light related to what I think is ICM so new gm icm & map sensor on the way. My plan is to keep it a driver and rebuild everything slowly. Get all the supporting pieces set then when the motor gives but in a healthy 350 vortec maybe with a edelbrock proflow but motor is last.

So far I have done:
- new optima red top, 1/0 battery cables, 6awg alt with circuit breaker, 2 new ground wires, some sleeving of wires
- tune up (plugs, wires, coil, advanced auto distributor)
- gas cap, fuel pump
- precision weatherstrip for doors, hardtop, and tailgate (shop doing next week)
- window motors & door actuators (shop doing next week)

Now I am looking at going through the axles, suspension, and brakes. This is a stock or pretty dang close to stock with no lift and will probably never be taken off road. Sadly the gf would kill me as I would love to lift it 2". My questions is should I look at staying stock style components or looking at ord crossover steering. Also I plan on doing better brakes with wilwood calipers but is there a larger front rotor I can do as well?

My rough plan is
- falken at3 31s with stock 6 lug rally wheels
- red head steering box
- ord steering box reinforcements
- ord hd tie rod with hd tie rod ends
- ord shackle & leaf spring bushings
- napa blue ball joints & wheel bearings/seals (mile marker hubs installed already)
- yukon axle shafts w24122 front
- bilstein shocks for stock height
- willwood D52 front calipers
- rear disk brake conversion
- rear seals and wheel bearings (might try and find a 12 bolt or go better axles with locker)

 

[Blue85]

Wow, looks nice. How wide are those wheels?

You can't really fit crossover steering at stock height - or at least it's enough work it wouldn't be worth it. I can't see any reason to swap to a 12-bolt. It's really no stronger than a 10-bolt and is sure to be older. Probably a good idea to go through the rear diff. Get rid of the G80 locker if it has one and put in a nice strong diff, like a Tru Trac.

What gears does it have? When going through the axles would be a good time to go to 3.73 or even 4.10.

 

[rampage]

What’s that going around the door frame, an antenna?

 

[83ChevyK5Blazer]

Looks like old weather stripping. I wouldn't waste the money on crossover. It isn't needed with stock suspension.

 

[muddybuddy]

What’s that going around the door frame, an antenna?

Remains of a stick on plastic rain guard

 

[rampage]

Remains of a stick on plastic rain guard

That’s it!

Goo-gone or kerosene (IIRC) will clean that up.

 

[chappys4life]

Wow, looks nice. How wide are those wheels?

You can't really fit crossover steering at stock height - or at least it's enough work it wouldn't be worth it. I can't see any reason to swap to a 12-bolt. It's really no stronger than a 10-bolt and is sure to be older. Probably a good idea to go through the rear diff. Get rid of the G80 locker if it has one and put in a nice strong diff, like a Tru Trac.

What gears does it have? When going through the axles would be a good time to go to 3.73 or even 4.10.

I have to measure the wheels. They where on there. He liked a car ride so would get wide wheels, michelin 31s, and run the pressure a little low. Smart idea but I love the 6 lug rally wheels. He had a set of center caps so now just finding wheels.

Im pretty sure its 3.55. I havent had the cover off to do fluids yet. Im in texas the highways are fast so no 34.10s. Sounds like I will do yukon rear axles with maybe a tru trac.

 

[chappys4life]

What’s that going around the door frame, an antenna?

Its the old side window deflector adhesive. It still has the driver side but the passenger side was gone.

 

[chappys4life]

Also with this many miles I have no idea the last time the trans fluid was changed. Do I risk it and change it? Its a 700 r4. It has a ecm chip for better shift points but I know nothing else about it. He was towing too big of a boat for it so he tried adding some things and disconnected the abs computer and the factory lockup harness on the trans. Slowly fixing bits haha

 

[muddybuddy]

Towing big boat with a high mile 700r4? eek. How does the fluid look? I would probably make sure its topped off and run it, knowing its likely on borrowed time

 

[Blue85]

disconnected the abs computer and the factory lockup harness on the trans.

Pretty dumb to eliminate lockup. Gives a tick more power, but likely fries the transmission. Drive in 3, not D until that's rectified. Hopefully he towed slow, in 3. (Of course unplugging the transmission is still stupid.)