L31 into an '86 Regal Limited V8

[ATL Regal]

I have a 1986 Regal Limited with an Olds 307 in it. The 307 never was enough power for me and in 2006 I broke it, bought a 97 Sierra with a 5.7L Vortec and parked my regal.
Last July I wrecked the truck, totalled it. I kept the truck and took the 5.7L Vortec, engine code L31, out along with the trans(4L60E), computer, engine wiring harness, driveshaft, radiator, and other misc. stuff.

I wanna know how hard it's gonna be to get the L31 in my Regal Limited and still have A/C, Cruise control, and keep my fuel injection and computer. I know everybody seems to feel like it's easier to do the swap by deleting the fuel injection and computer and just bolting a carb on top, but that's not what I want. I don't want this engine without the F.I., to me, that's part of the appeal of these engines.

I specifically want to know about the wiring. I have the complete engine wiring harness, all the way up to the bulkhead, from the truck. My question is how hard is it to wire into my current setup?
I have added a digital tach, digital speedo, and digital temp gauge all on the A-pillar that I want to wire up. Will I be able to use these and will they be accurate? If so, what's the best way to approach it?

The more I think about the swap, the more I realize that this engine is really a self-contained system and I shouldn't have any big problems. Although, I'm still apprehensive about the fuel plumbing and the dilemma of the fuel pump & location.


Any advice/suggestions appreciated!

TIA!

 

[bobcat]

Sounds like a nice swap to me. I'm not familiar with the Olds stuff, but any 305 car can donate mounts for sure. Trans mount may need some modifying, but I'm sure it wouldn't take much. As for wiring, just pare the engine harness down to what is absolutely needed. The Vortec probably has some senders and stuff you won't need, and once you eliminate them you'll find it a lot less intimidating. The AC shouldn't be too bad, the clutch will still be 12 volts, you just might have to interface the old harness with the new for idle-up. You will need to add a relay and a fuel pump (if you didn't save them from the truck), but that really isn't a big deal.

Good luck and keep us posted!

 

[Doober]

If you're keeping the engine relatively stock, it will be a little easier because you should be able to reuse the manifolds. The Vortec motors moved the EGR system from the heads to coming directly from the exhaust, so you need a set of headers or manifolds with the correct fitting (you'll see the pipe that runs to the front of the intake from the driver's side manifold). It should be a fairly straightforward swap compared to most other late model EFI swaps, you'll just need to have the computer reprogrammed to remove the factory VATS, you should also be able to get the post-converter O2 sensors deleted. There are shorty headers available, and far as performance exhaust goes they will probably be the easiest, I'm not sure you'll be able to run longtubes designed for the C/K trucks (partially because of engine bay clearance, partially because of ground clearance). Other than that, you'll just need to get a 700R4 crossmember (same trans, just electronically shifted) and a driveshaft to fit & you should be fine The later models also used quick-disconnect fittings for the cooling lines, but those can be changed easily enough if you don't want to use them.

 

[ATL Regal]

Still haven't started on this swap, but it's in the works.

First, I want to know about the mounts. Will I need some kind of kit to make the mounts fit? Where do I get the correct mounting plates or motor mounts?

I'm really excited, man. I've never done an engine swap before, hell, I've never even pulled an engine out before. I just want it to go smooth, don't wanna get in over my head.

Also, will I be able to use the radiator from my Regal? I still have the radiator from my truck, that goes to the L31, but it's huge. I don't think it'll fit.

Doober, what about the fuel lines? Mainly, the sending unit. I'm wondering if I can get a sending unit from a Grand National to go in my tank. I've read that the in-tank sending unit from 4.3L's will work as well.

 

[Doober]

Been a while since I've been on here...

Stock G-Body small block Chevy mounts work.

If you're going with a bone stock Vortec setup, you'll need to modify the lines near the engine to connect to the Vortec lines, but otherwise you can use stock TBI lines, a pump from a '96-'97 Vortec truck is a drop-in into the tank. You can use a stock G-Body radiator but I'm not sure how the upper hose routing will go... lower hose routing will be the same as stock G-Body.

What do/did you do for accessories?

 

[ATL Regal]

UPDATE

Ok, got the engine and trans in. Just bolted the engine to the mounts like 2 days ago. I'm now in the process of modifying the trans crossmember's center plate (where the trans mount bolts to) I'ma have to cut it so it clears the trans oil pan.

Quick question: The hump or hook(the part that looks like the bottom of a hockey stick) of the trans crossmember goes on the passenger side, right?

Now that I re-read this thread I see that you said I may be able to get a 700r drive shaft, I'ma look for one. I thought I'd have to get one made. I had to have one made for the '97 GMC Sierra(donor vehicle) when a tow truck driver damaged it, I still have it, it's aluminum and I was gonna try to trade it for them to make me another one for this application.

I'm kinda intimidated by the wiring, man. I can't really find any wiring diagrams. I bought a Dakota Digital Dash and I'm thinking about having a shop install it and do the wiring for the firewall conversion(Inside firewall: Regal wiring, Outside firewall: Vortec 5.7L wiring). FYI, I don't want to do this, I'd like to do it myself.

Just in case that is confusing... I have the entire wiring harness from the engine compartment of the Vortec donor vehicle all the way to the firewall. I didn't cut anything, just unscrewed the bulkhead, but the bulkhead connector for the Vortec is different from the bulkhead on the Regal.

 

[ATL Regal]

Been a while since I've been on here...

Stock G-Body small block Chevy mounts work.

If you're going with a bone stock Vortec setup, you'll need to modify the lines near the engine to connect to the Vortec lines, but otherwise you can use stock TBI lines, a pump from a '96-'97 Vortec truck is a drop-in into the tank. You can use a stock G-Body radiator but I'm not sure how the upper hose routing will go... lower hose routing will be the same as stock G-Body.

What do/did you do for accessories?

As you can probably see, I left the accessories exactly as they were when they were in the truck.

Have any suggestions or tips concerning the work I have ahead of me?

I have more pics, and I could take some more if you want to see something specific.

 

[ATL Regal]

I'm thinking about these headers, but I'm really kinda lost
http://www.summitracing.com/parts/big-11502flt/overview/make/gmc

I searched for:
Make / GMC
Engine Size / 5.7L/350
Engine Family / Chevy small block Gen I
Department / Exhaust
Section / Headers
Header Style / Shorty
Engine Swap / Yes

What's the best way to go about choosing headers for a swap like this? Trial and error?

 

[bigtmoney]

Im subscribing since this should be a cool thread. Im currently building a Vortec headed 350 but going carbed since i didnt want to mess with wiring Up the computer.

I converted my regal to the in tank EFI setup using a 4.3 Monte sender and pump from the scrap yard. I used the racetronix Hotwire kit to power it and had to run two lines back to the tank. I also use a Holley bypass fuel pressure regulator to send fuel back to the tank. So the fuel system will probably be way easier than adapting all the engine controls into the car.


Sent from my iPad using Tapatalk HD

 

[ATL Regal]

What's the best way to go about choosing headers for a swap like this? Trial and error?

I'm heading down to Summit to get some stuff, I really wanted to have this question answered by now.