Small Block Interchange-ability across years? How to put a 97 Vortec Motor in a 92?

[fishmunger]

Hey gang,

So I got a 97 GMC 2500 (heavy half) extended cab, short bed, auto trans, 2wd. Nice truck, I had a vortec crate motor installed in it a few years back when the original engine blew. The motor has less than 50,000 miles on it now, runs great. But unfortunately I had a BFG all terrain come apart and mess up the bed pretty bad. Clean truck otherwise, been driving it like that for a few years but getting kinda sick of the damage. Have considered swapping beds from a donor truck but I really wish this truck was 4wd.

So a good friend is the original owner of a very clean 1992 K2500 reg cab long bed. He recently got a new truck. The '92 probably won't pass smog much longer (has a leaky valve guide). I could get his truck fairly cheap I think, probably a couple grand, maybe less, and like I said its a very nice truck and 4x4, unmolested.

How hard would it be to drop the motor from my 97 into his 92? Is it pretty much a bolt in type of deal that I could get done in one long day or maybe 2 at most? I'm not looking for a big project, and I'm concerned that putting his tbi stuff onto my vortec motor might be problematic? I can turn a wrench but I'm no engine tuner, and I've never swapped a motor before but am mechanically inclined (I do most all of my own work/maintenance) and I don't want to get in over my head having to modify or troubleshoot stuff. It's also important that it looks/works right afterwards because here in CA I got to pass smog.

What do you guys think? Is this worth doing? What issues should I expect?

Thank you

[Mr_Rich]

I don't think this would be a good project for a first-time engine swap. Like-for-like would be okay, but I think there are issues that would be difficult for a first-timer.

[b454rat]

Its not that bad. You will need a TBI/Vortec intake, everything bolts on, it's still a small block. Some will say you will need a custom PROM for the ECM, but I built a TBI406 using the stock fuel, ecm, and prom and didn't have an issue. So with as mild as a Vortec is, don't think it will pose any problems.

[Kudzupatch]

Just about to do this swap in 1993 Suburban. Done lots of homework and reading on this. The motor will bolt in no problem. The issue is in the TBI from Vortec. That is not straight forward bolt in. Not that hard but if you want to get the engine running right you are going to have to have the computer program tuned to match that engine and no many people will work on the older OBDI systems.

I have lined up an open minded tuner and I am going to install a Chip Emulator. Moats Ostrich. It takes the place of the chip and allows the tuner to connect a computer to it and make changes real time. So as soon as I get it running it goes straight to the Tuner.

[speedygonzales]

Your header on the thread says you want to put the complete Vortec into a 92. Not sure why you mention mixing TBI with Vortec. I don't see you mixing engine parts.

We would assume you will move the engine, the PCM and all the wiring over to support the engine. You will then need to swap instrument clusters because the Vortec dash is run differently then the TBI.

The only thing in the old chassis that you might have wanted to leave behind would be EVAP and the fuel tank/pump. Don't forget ABS.

Those 3 systems will have to be changed as well. The TBI fuel system does not have enough pressure compared to the CSFI on the Vortec. I'm not sure the pump in the TBI could produce enough pressure. So you should expect to have to move the tank with the Vortec pump and all the lines over to the 92.

The lines hook up uniquely to a CSFI at the intake that no other style used. If the trucks are different lengths there may be an issue you will have to deal with.

The evap system will also be different as there are lines that run from the CSFI intake to the charcoal canister.

There could be issues with the radiator hoses connecting due to differences in the sizes of radiators. Be sure you check the 2 before you so the switch.

So to summarize (assuming you leave the Vortec engine intact).:

Engine swapped
All wiring swapped
PCM swapped
ABS swapped
Instrument cluster swapped
Fuel system and lines swapped
Evap system swapped

Not sure your entire issue but it may be easier just to swap the 92 body onto the 97 frame. Then just change the instrument cluster. Just a thought.

At nearly 60, I wouldn't attempt you want to do. Way too much work.

[fishmunger]

Thanks so much guys, sure am glad I asked. That’s a bummer that it’s a PIA with the vortec to tbi. That’s kinda what I suspected. So the simplest way would be to swap a tbi-compatible manifold onto my vortec, but it sounds like I’d still have quite a bit of troubleshooting\tuning to do. Sounds like I could quickly get in over my head.

[Kudzupatch]

It would probably run with the stock tune, but it is definitely not going to be anywhere near all the motor has to offer. Power or MPG. If you can find a tuner that is knows what he is doing, the chip emulator is $150 so it isn't that expensive and you can sell it and recover half that once you are done.

[Mr_Rich]

For all of you out-of-state guys: your suggestions are good for out-of-state swaps. This is California which makes the swap for the OP a PITA X10. I've gotten gigged for a re-routed PCV hose on my LS swap which was actually a factory improvement. I still think a newer engine swap like this for a first-timer would be very difficult without some serious mentoring all through the swap. Nope, nope, nope.
And then, to top it off, OP would have to take the vehicle to a referee station to get the sticker to pass smog checks. Complications before and after...

[sntrym95]

It's not a bad swap, but in CA it will be a PITA to pass smog. I did it on a 95 Yukon and there was some fabrication of the brackets (Vortec bolt pattern is different) for the throttle/cruise and MAP. I used a chip from Brian at tbichips and it's been perfect. I also had to upgrade the fuel pump and diaphragm in the TBI to an 18psi spring. There were a bunch of other parts too, listed here: https://67-72chevytrucks.com/vboard/...1&postcount=11

[AussieinNC]

As you are in CA...this exercise would be a total waste of time...and frustrating beyond belief....

Grab a standard GM replacement long block for the '92' , comes with warranty and will work with all your original options...put a new radiator and hoses and water pump on it and enjoy....

or

Put a bed on your 97 and enjoy....

Do you really need the hassle?

[fishmunger]

You guys are right! Not worth the hassle! I'm glad I asked.

[1976gmc20]

Can't you just get the heads rebuilt on the 1992 and run with it ???

BTW, I would LOVE to have that K2500 reg. cab long bed if it was a manual. Too far away but if it's not using too much oil it could probably just be driven for a long time in Montana ....