Bought a one owner 80 Eldorado that factory was an Olds diesel, many years ago (late 80s) he had the dealer toss the diesel and swap it for apparently a 455. The cars last registration was 98. He says he only put about 30k miles on the motor. It runs excellent.
the only Olds engine ive owned was a 79 Eldorado that came factory with a 350 olds , Cadillac port fuel injection system. I would like to know what engine I have in this 80 and what year if possible.
How could I tell?

Matt

 

If it is a 455("F" block) the "C" heads would make it a '68 or '69. That things gotta move!! They pretty much doubled the horsepower from a gas engine from that year.

 

Back in the day, most of the diesel units were converted to 350 Olds gassers. But according to propaganda from 1980 for the Toro, the 307 was an option!

 

That has to be a really nice car, luxurious but fast! I'll bet you could surprise some street racers with that thing, as long as the front tires don't go up in smoke!!

 

Engine year will be second number from left on this pad.
3=Oldsmobile
9=1969
M=Lansing Michigan
123456=Vehicle Identification Number of car

From the 'C' heads your engine should be a late 1967 thru to 1969 engine block

 

Let's back up. Start with identifying which BLOCK is in the car. The heads can be bolted to any Olds block. Check the block casting number above the water pump.

 

Wow, interesting. I was expecting a J head smog motor and probably a reman if from a dealer. I am guessing a 68 or 69 Tornado 455 was found complete with low miles too swap in. The low profile Tornado intake is needed to fit under the hood correct? Or is that just earlier models? It may be a touch faster than the original diesel but also much thirstier.

 

Why guess when the block casting number and VIN derivative will provide real info?

 

I wonder how different the front end and transmission is from earlier Eldorados that were equipped with 500's. My concern would be can the drivetrain take the torque of a 455 if pushed.

 

A 1980 Toro/Eldo would have come from the factory with a TH325 three speed transaxle. The TH325 is based on TH200 internals, so your concern is justified.

 

Nice find/car.... I wish i could have found it....

 

Thanks guys. I'm really excited about this car. I've been a Cadillac fan my whole life and always loved these E bodies.. this one feels like the holy Grail for me. She's a keeper for sure. So what I was able to gather from above the water pump it looks like 338021..? I need to clean some scale off to get a better look but that's what I can see for now.

As mentioned earlier yes these came with a thm325
That also concerns me as far as longevity goes. I gotta be sure to keep it easy from the start. I know a guy named Bruce Roe that has a 79 Eldo that he dropped in an Olds 403 and built a thm425 switch pitch trans for. Apparently there was major fabrication to get it in. Custom brackets, some frame mods I believe. Not something I would be able to do so I'll have to make sure I keep the 325 alive.

 

Look again. It's 396021, which is a 455 casting. As shown above, now check the VIN derivative stamp for the exact year.

 

Ok I see it. Thanks.
Found the stamp on the left side, here's what I think it says... 38x16352. Does that sound correct?

 

Yup. The "8" in the second position is 1968 model year. The "X" in the third position is Fairfax, KS assembly plant. Fairfax only built full size Oldsmobiles in the 1968 model year, so this is a 455 from a Delta 88 or Ninety Eight. Unfortunately, there is no way to know if it was originally an L30 low compression 310 HP motor, an L66 high compression 320 HP motor, or an L31 high compression 365 HP motor. All three were available in full size cars in the 1968 model year.

 

Nobody mentioned it but that is a very nice looking car. Congrats on the purchase.

 

Those Eldorados were beautiful cars, always one of my favorites too. Too bad more years than not got the 4100 engine. I had a 72 for a first car during the 1990's. It was very dependable.

 

Thank you man! I'm pretty excited about it. So far the only fixins it needs is rear shocks, plastic bumper fillers are brittle and falling apart, and the antenna stays up. Very Happy with the purchase.

Thanks to everyone that helped me identify the power plant! That's pretty cool it's a 68 455. This is gonna be fun

 

If It's a 2 barrel it's either a L30 or L66 engine . If it's a 4 barrel , it's an L31 365 HP motor .
Provided that the manifold is original to the motor .

 

It does appear to have a 2bbl intake???

 

toro intakes were all 4 bbl.my toro gt engine has a 2 4bbl intake.

 

I am surprised it fit under the hood, unless that is a very drop base air cleaner. What are the numbers on the intake?

 

This isn't a Toro motor, it's out of a 1968 full size. Also, the later Toros don't require the depressed intake of the early cars.

 

I wish Caddy stuck with that FWD layout. I hate sideways engines. When I was looking to replace my 72 Eldorado I saw a beautiful 79 with a 350 olds and a 71 Sedan Deville (I already had a 71 Coupe Deville also). Very unusual for a new car dealer to have two old cars on the lot but both were in beautiful condition. I later called about the Eldorado but someone else snagged it. I ended up buying an 88 caprice from a family friend, which served me well.

 

Cool car especially with an Old School 455 wedged in the bay.
Yes, I too would be concerned about the small trans-axle. No smokey burn outs for you. When it does go I bet the typical 200 performance upgrades would apply. If so its worth it.Or graft in a THM425 out of an old Eldo/Toro?
I had a 71 Eldorado Vert with the 8.2L aka 500" Cadi motor. All my friends referred to it a the "Velvet Hammer". I installed a better cam, tweaked the carb, shaved the heads and dropped in a re-curved 76 Eldo HEI. It was a torque monster. Would roast the front tires at-will and feel like you were riding a lazy-boy down the road. Awesome ride. Id buy another if I had room.

 

A beautiful Eldo, with a strong 455 Olds engine, what's not to love? Even the weakest of those 455s will project that car very nicely! I do wonder, as others have said, how long the transaxles will hold up, but if you don't abuse it, it should be ok. Good luck and enjoy!

 

Thanks for all the good words everyone! It really solidifies my thoughts on purchasing this car. I am more excited than you can imagine. I did have a 79 for about 5yrs that had the old 350 and I loved that car, the factory analog EFI system went to crap so I converted it to an aluminum intake and 4bb. It was a very reliable car. This tops that now and I feel like I'm back at it!
Yes it is a 2bbl, I would like to replace it with a 4bb.
I'm into Buick GSs and we always recurve them where they like them at low RPM. About 32-34 total, 12* initial, 22 advanced all in by 2400 or so. And about 8* on the vacuum advance. I would like to go through everything thing and make sure it's where it should be on this 455... Any advice on what timing and curve they like?

 

Welcome Matt. I took an 81 Coupe Deville with a crapped out Olds diesel and dropped a 403 out of a 77 Delta 88 in it.
It was easy peasy to do. A couch on wheels, enjoy.

 

Later Toronados and Rivieras had a 4 speed transmission I think was a derivative of the 200R4, maybe one of those might fit easily, and can be beefed up in the same manner as the rwd transmission?.

Roger.

 

The 325L4 is just the 325 with an extra overdrive gear set and clutch pack on the drive sprocket for the roller chain. The internals are pretty much the same, and yes, they are derived from the TH200 and 200-4R. That's not a good thing...

 

Hmmm, I recall reading plenty of posts about building 200R4's to handle lots of power, the GNX Buicks had them from the factory. Not cheap to do mind. But I never heard of a TH200 having the same treatment, maybe because it is easier to find a 350 or 400 and fit that instead.

Roger.

 

Would a 325 respond to the same mods as a 200 to make it a little less destructible? Barring that, how much difference size-wise between a 325 and a 425? In other words, would a 425 fit in there?

 

Some of the parts interchange, some do not. A person would need a break down of each and see what exchanges. Then there are the unique parts like the chain drive.

 

Externally the over dims are in the ball park but likely not a bolt on fit? Its been way too long since I've looked at either drive trains to really give you a yes no answer.

The 400/425s case is slightly larger to house the larger internals. Internally the guts of a 400/425 is at least a 33% to maybe as much as 50% larger. Gut a TH400/425 and a TH325/200 etc and you will be impressed at the beef in a 400 compared to the lesser transmissions. Day to night IMO.

You may or may not be able to directly bolt the 400/425 to the existing axle flanges and mounts?? Might need some ingenuity. Of course the next weakest link would be the CVs and axles...To solve this you will likely need to get aggressive and cut up a 66-76 and graft the whole front half into the yours? Or at least the structure that holds the 425 axles and other components. Could be easy or not. At minimum an axle upgrade could/would be required.

The current trans, the 325 can most likely be upgraded to survive smooth cruiser duty. You have to find someone with the right knowledge and familiarity to preform the required upgrades. Again as long as your not smoking the wheels at each stop it will likely survive with regular fluid and filter service.

 

It's definitely not a bolt in to the frame. The mounting provisions on the TH425 are completely different from those on the TH325. You'll need to fabricate brackets at a minimum, and likely will need to mod the subframe.