My Cutlass Engine Swap

[DoctorSwain]

I posted here last year and got a great response so here is an update on the cutlass:

Last summer I pulled the old 3.8L v6 from my 1983 cutlass supreme brougham edition. After I pulled the engine I realized it had a hole blown in the engine block so I took off all the parts that I could reuse. In the meantime I searched high and low for another v6 for a restoration. I couldn't find an engine, but I did find an 1980 Oldsmobile 4 door Cutlass in located in Billings, Montana with a working v6 engine. It was painted primer gray but aside from a cracked grille, cracked headlight bezel, broken turn signal, and somewhat rough headliner/interior, it was in good shape. The heat worked, but it had no radio. The key was stuck in the ignition. The interior was faded, but it was mostly rust free. It had the normal 40 year old car problems, but it wasn't bad.

I took a greyhound at 3am to arrive in Billings and meet the owner at 7am. Right before I left my dog got out and got sprayed by a skunk. It was a chaotic trip but I made it happen and bought the car. The guy selling it was generous and took it down from $1000 to $700, gave me some oil and coolant, signed the paperwork and I was on my way. I drove it 150 miles back to Bozeman and stopped once to top it off with oil. It rode smooth like a cutlass does. I got back home around 11am feeling quite good albeit a little tired from not sleeping.

I had every intention of swapping the v6 into the 83 two door at that point, but after a few days passed I decided I wanted to keep the 4 door. My plan changed to painting and restoration on the 4 door and upgrading the engine in the 2 door so it could boogie. On the 4 door I fixed the bezel, turn signal, and grille with parts from ebay. I stapled the headliner up, installed a new ignition lock cylinder (made a video for that), changed the oil and bought new plugs, rotor, distributor cap, and plug wires. I registered and insured it and she's driving well to this day. The 2 door is sitting in the driveway with the hood off and a tarp over the engine bay.

My new plan with the 2 door is to drop in a carbureted sbc 350 crate engine and do all the necessary mods. The transmission is a TH350 with B.O.P bellhousing so I need the BOP adapter plate. I'll need a full engine, flexplate to fan, oil pan to carburetor. I'll need to replace the coil springs and fix up the suspension using new ball joints, control arm bushings, tie rods, steering linkage, sway bar. Also, I need a v8 fan shroud, engine to bracket mounts, clamshell frame mounts. I will need to reroute the fuel line to the passenger side. Also, I'll need the torque converter lockup kit and a couple six packs of beer. I will do everything in my power to make that happen this summer. I have been doing a lot of studying over the winter and it is time to revive the brougham.

Thanks for reading my story and let me know if I forgot anything. I'll be posting updates of my progress.

Engine Pull on the 83

'83 cutlass supreme brougham 2 door in the foreground, 4 door cutlass in the background

Engine bay of the 80 with the 3.8L v6

Engine bay of the 83 with the engine pulled

 

[5spdCab]

Cool that you now have two cars that are so similar in their care and maintenance procedure's.
Sounds like you thought things through pretty well. Others here have done the Chev into BOP swap. They will know more of what you are up against than I. My swap was Chev into GMC Caballero (El Camino twin cousin), so things went relatively well. I was able to reuse several v6 parts on the v8. Your fan shroud is very different from mine. I trimmed mine at the first structural rib and was able to reuse it. My first oil change required that I purchase a remote filter set-up because I could not get the filter out without removing the headers first, so if you plan on headers, make sure you have room to remove the oil filter. Rerouting lines might sound like a lot of work, but it is really just more time consuming than it is difficult. Good luck, keep us posted.

 

[DoctorSwain]

Cool that you now have two cars that are so similar in their care and maintenance procedure's.
Sounds like you thought things through pretty well. Others here have done the Chev into BOP swap. They will know more of what you are up against than I. My swap was Chev into GMC Caballero (El Camino twin cousin), so things went relatively well. I was able to reuse several v6 parts on the v8. Your fan shroud is very different from mine. I trimmed mine at the first structural rib and was able to reuse it. My first oil change required that I purchase a remote filter set-up because I could not get the filter out without removing the headers first, so if you plan on headers, make sure you have room to remove the oil filter. Rerouting lines might sound like a lot of work, but it is really just more time consuming than it is difficult. Good luck, keep us posted.

Thanks for the response.

I have been reading a lot and watching a lot of videos so for the most part I know what I have to do, I just have to start the work. Taking the engine out was a seemingly astronomical task but I just kept at it and one day the work was done. I feel that putting the engine in will be similar, just with a lot more money at stake. I never thought about the oil filter placement in relation to headers. The book I have, GM Performance Upgrades, discusses header clearance in relation to the control arms so that was one of the places that I thought they might interfere with other parts. I will definitely check to make sure of the oil filter placement on the new engine.

I have seen swaps where someone trimmed there fan shroud like you said and it seemed to work fine. As far as I know, it's mainly to hold the radiator in place and for safety of course. I'd like to get the v8 shroud so I can keep the v6 shroud as a backup for the 4 door. With all the parts I pulled from the v6 in the 2 door, I have backup parts for just about everything on the 4 door v6. That is a good feeling. Also, like you said, I know the care and maintenance routine for both cars quite well at this point.

Good to hear that rerouting the fuel lines isn't difficult. It seemed like people just get a hose and route it in a convenient spot across the front or under the front of the engine. I will check out other threads on the BOP to chevy conversion and see what they say. It seems like it's not that bad. What seemed like the most difficult part of the swap was switching out the frame mounts. I know I will have to do some tricky moves with ratchet knuckles and extensions to do it. It'll probably be easiest to remove the upper control arms first, but they are extremely rusted so we shall see how that goes.

The Caballero looks like a sweet car. It's always nice to hear of someone else doing an engine swap in a gbody. I will post updates of my project as I go on.

 

[69hurstolds]

One thing about your new car that bugs me a bit...

...you said you had to stop and top off the oil in your new V6 for a 150 mile trip? Is it because it leaks, or is it consuming the oil that fast? It's just a bit concerning is all. Other than that, sounds like a nice score for the money.

 

[DoctorSwain]

One thing about your new car that bugs me a bit...

...you said you had to stop and top off the oil in your new V6 for a 150 mile trip? Is it because it leaks, or is it consuming the oil that fast? It's just a bit concerning is all. Other than that, sounds like a nice score for the money.

Honestly I am not sure. I've had it parked outside my house for months and there's no evidence of leaks. Also it hasn't needed to get topped off since I changed the oil. The oil is still a nice color from my oil change whereas it was quite black when I bought it. The valve covers look like they're leaking a little bit but that's all I've noticed. So how it burnt/leaked a half quart of oil in 70 miles is a mystery to me. My only guess is that maybe the oil drain plug wasn't screwed on tight or it was having trouble going highway speed for that long and it was burning up oil.

 

[5spdCab]

Thanks for the response.

I have been reading a lot and watching a lot of videos so for the most part I know what I have to do, I just have to start the work. Taking the engine out was a seemingly astronomical task but I just kept at it and one day the work was done. I feel that putting the engine in will be similar, just with a lot more money at stake. I never thought about the oil filter placement in relation to headers. The book I have, GM Performance Upgrades, discusses header clearance in relation to the control arms so that was one of the places that I thought they might interfere with other parts. I will definitely check to make sure of the oil filter placement on the new engine.

I have seen swaps where someone trimmed there fan shroud like you said and it seemed to work fine. As far as I know, it's mainly to hold the radiator in place and for safety of course. I'd like to get the v8 shroud so I can keep the v6 shroud as a backup for the 4 door. With all the parts I pulled from the v6 in the 2 door, I have backup parts for just about everything on the 4 door v6. That is a good feeling. Also, like you said, I know the care and maintenance routine for both cars quite well at this point.

Good to hear that rerouting the fuel lines isn't difficult. It seemed like people just get a hose and route it in a convenient spot across the front or under the front of the engine. I will check out other threads on the BOP to chevy conversion and see what they say. It seems like it's not that bad. What seemed like the most difficult part of the swap was switching out the frame mounts. I know I will have to do some tricky moves with ratchet knuckles and extensions to do it. It'll probably be easiest to remove the upper control arms first, but they are extremely rusted so we shall see how that goes.

The Caballero looks like a sweet car. It's always nice to hear of someone else doing an engine swap in a gbody. I will post updates of my project as I go on.

Rerouting the lines with extra hose (or tubing) IS what I was referring to. Unless I was doing an extensive restomod full rebuild, I would just extend and route the lines to the needed location.

 

[DoctorSwain]

Rerouting the lines with extra hose (or tubing) IS what I was referring to. Unless I was doing an extensive restomod full rebuild, I would just extend and route the lines to the needed location.

That's the plan once I get to that point. I was out working on it today. Trying to get the control arms off is quite tough, but the driver's side bottom one is almost off. I need to disassemble the tie rod to get the front bolt out. Suspension can get a little tricky.

 

[5spdCab]

That's the plan once I get to that point. I was out working on it today. Trying to get the control arms off is quite tough, but the driver's side bottom one is almost off. I need to disassemble the tie rod to get the front bolt out. Suspension can get a little tricky.

That was another thing that I needed to do, swapping a v8 into a v6 suspension required stronger springs. I had never removed control arms prior. I compared both a Haynes and a Chilton's manual for the instructions to R&R the control arms, ball joints, bushings, and springs. The local machine shop charged me $30 each for replacing the bushings. At that price, it would have been less expensive to purchase a press from Harbor Freight (which I did when I replaced the rear bushings) and do the replacement myself.

 

[DoctorSwain]

That was another thing that I needed to do, swapping a v8 into a v6 suspension required stronger springs. I had never removed control arms prior. I compared both a Haynes and a Chilton's manual for the instructions to R&R the control arms, ball joints, bushings, and springs. The local machine shop charged me $30 each for replacing the bushings. At that price, it would have been less expensive to purchase a press from Harbor Freight (which I did when I replaced the rear bushings) and do the replacement myself.

Yeah, the bushing replacement seems pretty simple: once the control arms are out, press them out, press the new ones in. I may have to sand out some of the metal where the bushings seat for a smooth fit. The upper control arm has the shaft that you have to take out, but I just figure I'll use an impact on the outer nuts and it will hopefully go smooth.

The removal of the control arms was kinda tricky. I had done ball joints in the past but at that point I couldn't get the control arms off so I left the shot bushings on there. Also, the engine was in the car at that point. With no engine there, I have a lot more room to work. I've been at it for the past 4 days.

I removed the shock, put the coil spring compressor on, removed the sway bar linkage, then removed the tie rod. For the lower control arm, I removed the first pivot bolt, but the second one was kind of stuck. I used the impact on it and it came out. I popped the ball joint and the control arm came free along with the spring. For the upper control arm, I disconnected the brake line, popped the ball joint to remove the spindle, rotor, and caliper as one piece. Then I just removed the nuts connecting the control arm shaft to the frame. That was super easy but they were totally loose. I wonder if I lost all my driver's side shims at some point because the passenger side arm still has a bunch of shims. The bushings felt seized and the only play I was getting in the control arm was from that slack where the nuts were loose. Everything is rusted out and hard to budge but it is doable without cutting anything. Now that I've got all that out, I will replace the upper and lower control arm bushings, sand and paint the control arms, and replace the ball joints, sway bar linkage, tie rods, and steering components. I will get the v8 coil springs but O'reilly doesn't have them so I will have to order them online. Everything else I'll just get from the local store. I also have easy access to the frame mounts through the hole where the lower control arm was attached to the frame. One side is done and I'm working on the other side. My main guide for all this was my Chilton manual.

Pricing is: shocks will be $40 each (x2); Moog ball joints are $44 for the upper (x2), $43 for the lower (x2); bushings are $29 for the upper (x2), $30 for the lower (x2); tie rods are $30 each for the outer and inner (x2), Moog sway bar linkage are $16 each (x2), Moog coil springs are $66 a pair, center link for $61, idler arm for $25. So for $676 I will have a full front suspension rebuild. If I buy the ball joint press thats another $90 but I don't mind borrowing it from O'reilly which is what I usually do. I can't imagine what I shop would charge for what I'm doing.

photo of the control arms, coil spring, and rotor/caliper/spindle on the driver's side:

 

[69hurstolds]

A shop would charge you a butt ton of money, of course. While it's not a super-difficult job in and of itself, it's considered a major job to do all of it. Just make sure you don't swap uppers from one side to the other. That's been about the only common mistake I've seen when people tear them all the way down.

But that's why they make impact wrenches. For those bolts that don't like coming off.