What to pull from donor? (and how)

Hello everyone. I have acquired a 1991 Chevy 1500 full sized truck to use for parts. The main item I wanted was the motor (a 4.3L V6 with TBI). I have three burning questions I'm hoping someone can help me with:

1. When pulling the motor, should I separate it at the bell housing, or between the bell and the trans?

2. Those motor mounts look tough to unbolt. Any tips on how to get them loose?

3. Before I get rid of the rest of the vehicle, is there anything else besides the motor and computer that I should pull? Can I use the steering? Transmission? The radiator seems too big; don't think I can use it. How about the wiring harness under the dash? I pulled out the bulkhead fitting and plugs for the computer, but nothing else from behind the dash.

I'm not a Chevy guy, so there's probably a lot of obvious stuff for me to learn (such as they used metric hardware on these! Who knew?).

 

I'd keep the truck tell your done with the swap. There's a always little things you don't think of to pull.

 

X2 on that I forgot the ecm

 

definitely keep the hulk til you're done.

 

keep the truck till you are done then make a trailer out of the bed. They come in very handy. I have one and would like 1 or 2 more. I have seen my uncle tow as many as five pickup bed trailers around at one time even I am not that redneck.

 

Wish I could keep the truck, but the wife would be livid. It is sitting in front of the garage in our driveway, blocking the garage door. Had to put it there due to the slope of the driveway, and my feeling that the motor will be hard to move around on the puller setup, especially pushing it up hill to the garage.

Any thoughts on the motor mounts - which bolts to remove?

Thanks for your responses so far....

 

Doesn't the motor mount design on those have an approximatly 6" long horizontal bolt that you can just remove to separate the mount halves?

As far as pulling the trans, that is going to depend on what it is. I think the SM465 was still an option and with it, it would be easier to pull the bell-trany bolts. If it is the Getrag 5 sp or auto, the bell will need separated at the block or just pull as a compete unit-have done it both ways. You should be able to sell the trans to recover some of your expense. Some trucks of that era had a nifty under-hood light that has about 15' of wire on a crank reel and a magnetic back on the light-they are REALLY handy on a Jeep. Mine is mounted on the far right side of the firewall-

 

Wow duffer, that's a beautiful motor you've got there. Mine's not going to be quite so fancy, but it should still be a lot better than the old L-head transplant my CJ-5 came with. The nifty little light is long gone unfortunately, though I'll have another look to confirm.

There are hoizontal bolts through the motor mounts on this truck; it isn't obvious that the two halfs of the mounts would split if the bolts were removed. But, that would make plenty of sense. I'll give it a try.

I think the trans is the "getrag" type, as it purports to have both an "L" and an "OD" on the shifter. There is a PTO port on both sides of it. I don't think the SMs were laid out like that - but I've not been too close to one before. I've noticed some interest in those 5-spd transmissions for other swaps into longer wheelbase jeeps and other old trucks. If it doesn't seem too tough, I may try to pull the trans to recover some of my cost.

As for where to unbolt the motor from - I think I will try the block-to-bell bolts. It looks like I would have an easier time getting in there to unbolt them. Thanks so much for the advice.

 

If your going to run the TBI you'll need the fuel pump relay under the dash and the map sensor which might be mounted on the firewall. I'd also take the fuel pump out of the gas tank and try and convert it to use in the Jeeps gas tank. It's better to push gas out of the tank to your TBI than to pull it out of the tank with an in line fuel pump. Also, the prom chip in the computer is different between an auto and manual tranny if your changing from your donor vehicle.

 

This truck happened to be a manual shift, so the computer should be set up for that.

I thought the MAP sensor was a little nub mounted on the side of the engine block. Is that not the case? I haven't seen anything on the firewall that looked as if it could be one, but I'll have to check again to be sure. Thanks for the tips!

 

That sounds like the knock sensor? The MAP sensor or Manifold Absolute Pressure sensor has a vacuum line running to it from the throttle body. They are suppose to be mounted higher than the engine but I can't remember where Chevy put them. The sensor is about 3 inches long and one inch wide. It has a vacuum line going into it and a number of wires that plug into it. If you google MAP sensor it shows a picture. It's kind of funny, your doing the same thing I did 10 years ago. Took a 4.3 out of Chevy 1500 and put it in my CJ-7. Best upgrade ever.

 

Pulled a few of these. Best bet you can do is remove the front clip all together(tossing the electric fan/etc wires on the motor). remove the doors. Remove the windshield and torch through the A pillars just above the dash(torch out so you don't burn the seat)(LEAVE like a inch for later). unhook the clutch linkage making sure not to cut or disconnect the fluid line. Cut and pinch off your fuel/ break lines bending them up so they don't leak all over the place. Use a grinder and cut through the floor about 3 inches towards the drivers seat from the firewall(your cutting in front of the body mounts). Don't cut to deep or you will hit the bell housing. Your going to cut through some wires but it is nothing except lights and the fuel pump.

Pull your drive shaft(s)(and transfer case if 4wd) putting a Ziploc and some duck tape over the tail shaft to avoid it leaking. Using a floor jack jack up your transmission and remove the transmission cross member. Let the transmission down(it will drop like 2 inches). Put something under the tailshaft(The spare tire works good). Remove any wires that are hooked to the frame.

Get your cherry picker out and chain up the motor. Jack it up a bit to help you remove the motor mount bolts easier and remove them being ready for the motor to shift a bit. The transmission will drop a bit but won't hit the ground because of your tire/soft thing. jack up the motor a bit then. push the dash(from inside) against the motor. Get out some ratchet straps and ratchet the dash to the front of the motor(between the crank pulley and water pump) leaving it a bit loose.

NOW cut through the a pillar that you left and the firewall will shift down landing on the transmission bell housing(if it does not check your cuts while jacking up the motor. Jack up the motor/trans while tightening the straps against the motor. Pull the motor back slowly being careful to make sure the firewall is not hanging onto anything. Take your time here dropping the tire pressure may help. Then set the motor/transmission/firewall on a crate(put some wheels on the bottom of the crate or use a creeper) using another ratchet strap on the motor to keep it upright. put the motor in the middle of the crate

Now you can call someone to come and get the truck so they can get it today/later.

Now that the motor is strapped to the crate you can unbolt the cherry picker. Then move the cherry picker around and strap it to the firewall putting a bit of tension on it. Jack up the firewall while
Being careful(a buddy really helps here) un strap the motor from the firewall and jack it up(watching your wires that are still connected) you can push the firewall back or forth for better access then remove the transmission bell housing bolts.

Pull the transmission away and set the firewall back down against the motor (strapping it loosely so it does not fall when your away). now you can take as much time as you need removing(and labeling) all the wiring while having the motor/firewall taking less then 4' of space in your garage.

Sure I am forgetting a few things but you get the idea. Gets the truck gone leaving the motor and all the important wiring. And because you put the crate on wheels you can wheel it around if need be while labeling everything. Take pictures as you go it helps a lot.

 

Forgot the steering wheel.

You can take the easy route and cut through it the shaft after removing the break lines. Obviously before removing the fuel lines.
Or remove the bolts from under the dash and unbolt the shaft from the gearbox and simply beef it up against the header.

Forgot the exhaust. Simply cut it under the cast after removing the clip.

Make sure to cut the break lines under the abs block.

 

Hey guys, should I pull the power steering box? I'm not sure if it would have the right ratio for my purposes, or if it would allow fitment of a suitable pitman arm. Any suggestions?