Luke Merrick

I haven’t found any good sources on an LS swap for Toronado’s, and the only ones I’ve seen are models from the 80’s. So I was wondering if anyone could tell me about how difficult/time consuming/expensive it would be to do one. I know that on FB marketplace you can pick up an LS for about $500. I’ll just make some bullet points so it’s easier for me to explain, so here’s what I want and why.

-Better fuel economy, my stock 403 gets around 11mpg and is not capable of long distance travel, which is the ultimate goal. It’s not reliable enough, strong enough, of fuel efficient enough
-More horsepower, as stated before I want to take this on road trips, and comfortably run at 80+ mph on the highway
-Better reliability, My 403 has given me hundreds of dollars worth of issues for the carb, electronics, and general maintenance that the previous owner neglected.

With this all being said, if you can, please direct me on a good engine that would fit this criteria, while also being a relatively easy swap. I only want to swap the engine as I don’t have money for other components.

Bfg

I see a can of worms being open to do a LS swap

Olds64

There's no way to do an LS swap "on the cheap." One of the easiest hurdles to overcome would be adapting an LS engine to your transaxle or getting an LS4 (the only FWD LS engine) and 4t65e to fit in your Olds.

If you want to save money then tune the 403 in your Olds. It'd even be cheaper to pay somebody to do a tune up than doing an LS swap.

redoldsman

I think this would be close to an impossible swap.

BangScreech4-4-2

Anything is possible if you throw enough money at it. Just don't expect to recover much (if any) of it when the project is complete.

Bfg

By the time your done goofn around with this hodgepodge idea, you could have restored the whole drive train on the 78 Toronado and be money ahead! If your hell bent on a LS, go buy yourself a Chebby!

oldcutlass

The issues I see are the oil pan, engine mounts, exhaust, and the usual electrical conversion issues. I would think a transmission adapter plate should work.

66_Jetstar

You can adapt the LS to the bop trans, but exhaust manifolds or headers will be a nightmare. A good fabricator should be able to overcome most obstacles though.

Luke Merrick

I see all of your points, thank you for your insight, I’m pretty new to this stuff. Since an LS swap looks out of the picture, what kinds of mods can I do to my engine to get a sizeable amount of horsepower? I frequently travel 4 hours between home and college. 8 hour round trip. I know that as of now I could run 70-75mph pretty smoothly, but I know I can get more out of that engine.

Olds64

There are plenty of ways you can build a 403. Even in a Toronado. The real question is what you want to do with it? Race track only, cars & coffee cruiser or OE concours restoration? Also, what is your budget?

BangScreech4-4-2

Agree, the build depends entirely on planned usage. It sounds like OP wants to use it for a daily driver, which in this day and age may not be the most practical choice.

fleming442

A fwd LS4 from an Impala would be the only thing I'd even try. If you were really lucky, the whole subframe would swap in. I don't think it's very common, so you'd be breaking new ground.
Then, decide on power (adder) level. HP Tuners is all but obsolete these days. An aftermarket ECU/PCM would be more expandable.

Luke Merrick

I understand that it isn’t the most reliable/realistic daily driver, I’m trying to convince myself to fix her up. The reason why I have these crazy ideas is because this was my first car. And by some miracle it hasn’t been sold yet. The car sat for roughly 17 years in someone’s yard which is why I consider swapping the engine. Now that I know it’s a bad idea I’ll probably get a four barrel carb and rebuild the engine. With all of this being said, if I put in the work, throw together some cash, and make it happen is it a realistic goal to have this as a daily and not go broke from it?

Edit: I just saw a post with a question about my budget. I’m a full time college student if that answers your question. Mods will be far between while I earn the money.

Other edit: I have a listing on FB marketplace that’s still up that my dad made, feel free to check out what the car looks like. Won’t let me post links but if you set the location to Nampa Idaho and look it up it should be there as a red-ish brown color in a garage

fleming442

The only question is: how bad do you want it? Finding some shop to take it on presents very slim odds of getting it done correctly and in a timely manner. If you do your homework, take lots of measurements, and get a reasonable game plan together, you could conceivably have it done over winter break. Or, plan all winter and gather parts for next summer.

75 W-30 H/O

There's always the Cadillac 472/500. Probably hard to find these days but a simple swap.

jaunty75

I have a '78 Toronado as well. If your car has its original carburetor, then it is a 4-barrel Rochester. A 4-bbl carb was the only one offered on the Toronado.

I have a '77 Toro as well, and I rebuilt the carburetors on both of them myself after buying a $20 kit and watching a few youtube videos. If you have not done so with your car, I suggest it as a cheap way to gain some performance. Overall, make sure the engine is in good tune.

Why does it need rebuilding, anyway? How many miles are on the engine?

I don't get it. Isn't 75 mph good enough? Why is that bad but going 80 is better? Don't you get to and from college fast enough at 75?

The bottom line here is, don't let the perfect be the enemy of the good.

The 403 moved these cars just fine back when they were new, and it can do so now if properly maintained and tuned. These cars were never meant to be perfomance vehicles. They're living rooms on wheels. They move you comfortably and quietly down the road. Don't expect more from the car than it was ever meant to give.

Take the money you would have spent on rebuilding the engine or swapping in another one and spend it on your girlfriend instead. It's a much better long-term investment.

BangScreech4-4-2

Agree with Jaunty in that: don't spend a lot of money. Start with a general health test of the engine (@ minimum test for consistent compression and pressure test cooling system). If that checks out, continue with a change of all fluids, forensic tuneup and full brake/suspension inspection. If the car is viable, this should get you rolling and you can deal with additional issues as they pop up and as time and money allow.

Even at that, if it were me, I'd make sure I had another reliable vehicle for backup. I know these cars were perfectly dependable when new, but that didn't incorporate having them sit idle for 17 years.

Luke Merrick

Thanks so much for your insight everyone. It helps me out a lot. For those wondering, I would rebuild the engine after some time for a few reasons.

1. The engine sat for 17 years, a lot of the cooling components I’ve already replaced have been super rusty, like my water pump, couldn’t turn it with a wrench.

2. There were some issues with oil pumps for transmission oil and motor oil. This caused the motor oil to seep into the bottom of the block, and trans oil to go through cooling and then into the cylinders. I want to rebuild because of possible damage to piston rings and anything else the oils might have done. At the time I was living at home and when I expressed these concerns to my dad, he said that he’d look at it and I should keep driving it. Until he looked at it and found the issue, I put about 1,000 miles on the engine. So I want to make sure nothing needs replaced. As of now I wouldn’t know because immediately after fixing these issues my dad put the car up for sale, and took it off of his insurance as well as swapped the license plate over to an ‘88 Suzuki Samurai he bought. I drove it maybe once after replacing these broken parts.

I don’t think I’d rebuild it right away, I want to work on my carburetor first. As it turns out, whether stock or not, I just have a pos 2 barrel that has already been rebuilt once. I’m considering replacing it.

Olds64

If you put 1000 miles on the engine before your Dad switched the tags around just keep driving it. Even if the car leaks fluids, if it drives you can overcome any poor driveability issues with a little bit of tuning and repairs

jaunty75

None of this is a reason to rebuild the engine. Replace the water pump. Replace the radiator and any other cooling system components that need it.

I acquired my '78 Toronado after it sat undriven under a tarp in the former owner's yard for 14 years, pretty much the same situation as your car. I did replace the water pump, radiator hoses, thermostat, and I had the radiator re-cored. As an FYI, no one makes new replacement radiators for the second-generation Toronados ('71 to '78) that I have ever been able to find. Same-year Oldsmobiles that could have been ordered with a 403 (Delta 88, 98) used a different radiator that is available. It's not as wide left to right. It can be made to work but you have to use the upper radiator hose that's meant for a Delta 88 or 98 with a 403 as the Toro hose is too long. There is a new replacement radiator that will fit. It's a Duralast B624 from Autozone. It's meant for '90s-era Chevy Silverados and Tahoes, but it's a drop-in replacement in all respects except one. One of the transmission cooler line connections is offset by about two inches. I needed a new radiator for my '77, and I was able to get the cooler line to fit by a little strategic bending and unbending of it here and there. It's been on the car now for over two years with no problems.

Getting back to the long-sitting '78, I did put a breaker bar on the engine to turn it and make sure it wasn't seized, and it wasn't. I changed the oil on it, changed the spark plugs, put on new plug wires, made sure there was coolant in the radiator, put in a new battery, and turned the key. I put a few gallons of gas in the tank first as well, but I didn't try to drain out any old gas. I figured/hoped that the new gas would mix with anything old and work well enough, and it did. The car started fairly easily. I did end up putting in a new gas tank, redid the brakes front and rear, rebuilt the carburetor, and other things, but I've never had to touch the engine itself. It does not smoke. I figure why fix what ain't broken.

The key word here is "possible." Rebuilding an engine is not a minor undertaking both effort and expense-wise. There are ways to make sure your engine actually NEEDS a rebuild before starting down a road which sometimes leads to more problems than it solves.

Drain the oil and replace it, along with the oil filter. Drain and replace the transmission fluid and filter. Replace the vacuum modulator on the transmission. Put in clean anti-freeze. Than start up the engine and see how it runs. Most importantly, DO A COMPRESSION TEST. That's a simple but effective way to determine the condition of the engine. If you get good readings on all eight cylinders, the engine does not need rebuilding.

Are you sure it's a 2-barrel? Who would replace a 4-barrel with a 2-barrel on a car like this? How does it even fit? The intake manifold has an opening for the 4-bbl. Is there some kind of adapter? Did someone replace the intake manifold? It's likely the fuel line connection, throttle connections, choke, etc. had to be redone or adapted as well. Again, why would someone do this? If possible, take a photo of the setup and post it so we can see what kind of a Frankenstein setup your car apparently has.