Swapping 94 to 92

[brningdawn]

Hey guys, wanted some thoughts on what do to with my truck. It's a 92 GMC K1500 5.7 with the 4l60. The engine is on it's last leg. Compression is low in 7 and it some days it has a pretty loud knock. Other days it doesn't. Haven't tracked it down yet as I haven't been driving it except to move it around. The transmission was rebuilt maybe 20-30k miles ago.

This last week I bought a parts truck that is all rusted out but has an excellent interior and a good motor with only 138k miles on it. It's a 94 GMC K1500 5.7 with 4l60e. I'm swapping the interior over and am thinking about swapping the drivetrain as well. I had a guy offer me $600 for the motor today so I could sell it and go a different direction with mine.

If I swap the engine from the 94 into the 92 what problems might I run into? Should I swap the transmission as well as all the harnesses? I can't be certain the transmission is good other than first gear because the 94 has a broken torsion bar cross member making it undriveable. The 94 transmission is also really rusted at the mount and adaptor between the transmission and transfer case.

Would swapping just the motor be as simple as yanking the old one out and dropping the new one in with the 92 harness and then just swapping over the bracket for the TV cable? I'm not sure if the 92 harness will work with the 94 motor. It looks like the 94 has a 3 wire o2 and it has an electronic transmission so I know the harnesses aren't identical.

 

[Komet]

I'm pretty sure the longblocks are the same so worst case you'd just have to take everything off the old unit and put it on the new unit. More likely they're mostly the same and you can mix and match what's best. Just keep all your 92 specific stuff in the 92.

 

[Just Nobody]

Just swap it.....if both are TBI. I have a 92 K1500 short box that I am installing an engine from a 94 K1500 suburban. My 92 is also knocking, but don't use any oil and dont leak.

 

[Drunkcanuk]

As far as I know....if it's just the motor, just unplug pull and plug the new one back in. If you wanna swap the tranny over, that's when you would wanna start swapping harness, ECM etc.

 

[GoToGuy]

Keep it simple. You take the 94 engine strip it down to a complete "" Long Block " . Pull the 92 engine set it next to the 94. Swap all external sensors, attachments, ring gear, etc. Just like if you bought it off the GM parts shelf.
And now would be a good time to do a thorough inspection on pulleys, idler bearings, tensioner, water pump, easier now than after it's installed.
That's how I, we did our engine swaps most of the time. Unless a plan B was called for.
Good luck.

 

[someotherguy]

* '92 has the 1-wire O2 sensor in the exhaust manifold; the '94 (1500/auto) has a 3-wire just ahead of the cat and no provision on the manifold for the O2.
* '94 has an EVAP purge valve where '92 does not.
* '94 TBI may not have the stud on the throttle arm to hook up your throttle valve cable for the 4L60 (can't say 100% on this one but they did eliminate that stud as it was no longer needed since 4L60E hit the scene in '93.)
* '92 has the single stud air cleaner, '94 has 2 (easily changed, too)
* '94 uses the "split O-ring" style thermostat gasket vs. the paper gasket (this changed in '93 also IIRC.)

Other than that? Pretty much the same. I brought up all the differences I could recall, "just in case"

Richard

 

[Erik the Awful]

My son's '94 doesn't have the TV cable stud.

 

[PlayingWithTBI]

The 94 TB may have the round plug for the TPS where the 92 may have a flat one (I'm not sure of the cut off year) but, you can get an adapter pigtail for that.

 

[Schurkey]

Keep using the '92 throttle body on the '94 engine, which solves all problems related to TPS, air cleaner studs, and TV cable connection.

 

[someotherguy]

The 94 TB may have the round plug for the TPS where the 92 may have a flat one (I'm not sure of the cut off year) but, you can get an adapter pigtail for that.

Changed from flat to round in '91.

Keep using the '92 throttle body on the '94 engine, which solves all problems related to TPS, air cleaner studs, and TV cable connection.

Agreed, though the air cleaner stud situation is a simple swap, couple minutes with a wrench. The TV cable stud is the gotcha.

Richard