Hey guys I can get a 500cu.in Cadillac motor from my neighbor. I am not sure its condition but I know he bought an Eldorado and took the engine out of it, and he was going to put the 500 in his motorhome, but ended up using a 502 chevy. I may put the 500 in my truck. I'm not really sure what transmission I should put in it. I know the bellhousing has to be a BOPC (Buick Oldsmobile Pontiac Cadillac) bolt pattern. I've never done an engine swap, so this is new to me. Still learning about transmissions aswell. The power output on the 500 varied with the year, I'm thinking it isn't the emission clogged 190hp version. I will oblivously need something that will handle some power. Any of you guys running a manual valve body on the street in an automatic? I kinda like the idea of being able to shift an automatic, but not have to use the clutch. My truck won't be setup for drag, although I'd like it to be able to get some use out of it on the track. There is no track in my town though, I'll have to drive 5hrs or so. I am on somewhat of a budget with my truck. How much would you guys pay for a 500 Cadillac? I think if I do swap the Cadillac engine in, it will be stock or mostly stock, I may put a shot of nitrous on it, but I dobut it. I will have to change the radiator in my truck, I think a Corvette radiator is a drop in fit, and isn't too costly.
Ok, no indication of what kind of truck you are trying to put it in. Any B_O_P or Cad Turbo 400 in good shape should work fine behind the 500. I'm in the gathering pieces stage of doing the same thing with my 71 (non HAMB) GMC 3/4 ton pickup for a bit more towing power over the passes here in the northwest.
Great Engines and are torque monsters. See if you can get the TH400 out of the Eldorado the 500 came out of. Or get a BOP Adapter plate and put any Chebby tranny behind it. Parts for them are readily available anywhere and even though the Performance parts are a bit pricier, you can get about anything you want. do a google search for CAd 500 and it will point you in the right direction or Search the hamb its been covered. Price is somewhere above what you want to pay and below what the guy wants to sell it for.
If its HEI, then its a smog engine as far as I know. Use the Turbo 400 as it will withstand the torque over a 350. Even the smog 500 has lots of torque. When the industry dropped all the numbers on HP and torque the Caddy only suffered a 15 per cent drop in "net power" meaning it didn't lose much at all. Do a Edelbrock 2115 intake with the Q-jet if you like them and update the dizzy to the old style points dizzy and then add a Pertronix kit and external accel superstock coil. That should be enough to wake it up . The combinatioon of Accel and Pertronix is ok as the Pertronix has a 1.5 ohm primary and the Accel is 1.2. Did the same combo to my chevy with no problems.
The 500ci Caddy is a great engine for a truck, tons of torque, lightweight (only weighs 50 lbs more than a small block chevy), and economical (if you can keep your foot out of it) I have a 500ci caddy in my 49 F1. Since your engine is coming out of an Eldo, and they were front wheel drive, then it has the TH425 transaxle. The rear wheel drive cars came with a TH400 behind them which would be a great trans for your truck as well. Yes it does have the BOP pattern so if you want to go with a 4spd automatic then you have to use the 200-4R as the 700-R4 only has the Chevy bolt pattern (I think) The earlier engine are better (higher horsepower) and the Eldo engines were rated higher than the RWD engines. I think the 1970 500 had the highest horsepower rating. As Rich Rogers stated, if it has HEI ignition then it is a 1975 or 1976 engine which were detuned (they were still great engines) The good thing about it being an Eldo engine is that you probably have the rear sump oil pan which makes engine swaps that much more easier. A great resource for these engines is a book by Doc Frohmader titled "Big Inch Cadillac" where he takes one of these engines and makes a super torque monster that runs on pump gas. The engine made so much torque at such a low rpm that the dyno couldn't measure it. Beside the buildup in the book he also give tons of tech specs and parts compatibility info. I am in the process of building a MegaSquirt computer to make my 500 fuel injected. I have aquired the factory port fuel injection manifold, injectors, throttle body,etc and hope to make some progress on it this winter. A googe search for the 500 Caddy will turn up some great reading. There are even several speed shops that are building parts for these engines. One of them is here in my hometown; http://www.cad500parts.com/ These guys do amazing things with these engines. Sorry for the long winded post Bobby
This is a great thread. I have access to a 500 Cad too, great price, but just hadn't pursued it. I think I'll have to reconsider.......
Steve (OldSub) is putting a 500 caddy in his AD truck. The TH400 is the trans to keep in it. They are plentiful with the BOPC pattern. The stock 500 has plenty of torque, however minimal work is needed to get more out of it. They are not High RPM engines though as the bearing journals are huge and you would run out of oil film.
I have a 94 GMC Sonoma.. haha. I know its not a classic but, I figured you'd guys know best. I've been doing alot of reading on this site. I want to convert to carburetion. No computer stuff for me. I want it to be as simple as possible. The guy no longer has the Eldorado. Its been gone for ages, but he's kept the motor. I think I will keep it mostly stock. I kinda want to get some sort of fuel economy, my truck is light which is a double sided coin. Light will mean it should be able to get reasonable fuel economy and secondly light will mean the rear end will not want to hook up.
The biggest downside to these engines is the stock intake manifold. To fit everything under the low slung hoods of the 70's cars they dropped the intake down into the lifter valley. The air/fuel mixture actually has to go up into the cyclinders. As already mentioned, Edelbrock makes a great intake for these engines thats an easy bolt on power boost. Yes, the HEI distributor from the later engines will drop right in. I'm pretty sure that the 425 and 368 distributors will work as well as they are the same block. Bobby
Wow didn't know about the intake. I haven't seen the engine yet. I like the looks of a tunnel ram, plus it would give me an excuse to make a cowl hood. However, I am not sure if I want to drop the money on a tunnel ram for a single carb. I could make one as I can weld, but I'm not sure how I'd go about it. I've seen a post of a scan of an old magazine article on here, but it was missing a few steps. What about running a manual valve body on the transmission? Yes? No? I heard there not overly street friendly, but if its just something I have to get used to I don't think I'd mind it. I'd like to be able to shift with an automatic.
You will have to fire up the torch to get a Fat Caddy into a '94 Sonoma. There is no way to get "some sort of reasonable fuel economy" from that engine. Mid 9's to about 10 are best that I have seen.
I was told no firewall modifications at all. V8 swap mounts move the engine up a bit I think.. I don't expect great fuel economy. I'd rather be broke and have a smile on my face than have some pocket change and a darn 4 cylinder.
In that book "Big Inch Cadillac" they run a tunnel ram made from sheetmetal. It should be fairly easy to fab an intake for these engines as there are no coolant passages that go through the intake. The book is a great read and I highly recommend it. There are a couple of places fabbing tunnel rams for these but they are pricey. I think there are adapters available that will allow you to use big block Ford intakes (429/460). I think the big block Ford valve covers are easily adaptable too. I fabbed my own valve covers by combining the late model stock sheet metal valve covers with some early 50's valve covers (pic in my gallery) Bobby
I disagree. If you drive them right they can get reasonable fuel mileage......mid to high teens. The problem is keeping your foot out of the throttle as all that torque is fun...lol Bobby
Actually the HEI was also in some 74s. Our 1974 Eldorado Convertible had an HEI and then we picked up another 1974 and it was points. My wife owned the Eldorado since 1975 and it was all factory.
Mine started out with 3.25 gears and 9-10 mpg. With a bit of tweaking, tuning, and 2.75 gears it went up to 17 mpg. The massive torque pulls the 2.75s like it was nothing, so don't worry about lack of performance. I have no trouble at all pulling away very quickly from the usual "hot" cars that are out looking for showoff opportunities at traffic lights. If you are looking for the thrill of winding the engine, banging the gears, jerking the clutch and hearing the engine scream, you will not be entertained. You will instead get a steady, strong, smooth, uneventful pull all the way from start to finish. No banging, bumping, screaming or wailing. You WILL however, be able to look back in the mirror and see the hotrodder you left far behind you enjoying himself with all the winding, thrashing, and gear jamming going on inside his fast and fun car. It may feel like a smooth uneventful ride, but it will be a quick, smooth, uneventful ride.
well said different, The big Caddy just pulls the same throughout the RPM range. Im getting 11mpg with 3.27 gears.
Also, I can buy engine swap mounts for SBC's, for cheap. Can I use them with the cadillac? Oh, the Ford 8.8, the 'tallest' (I think thats how it goes) is 3.27, the highest is 4.10. The 8.8 will fit in my truck and is like ohhh 3" wider per side I think..
I kept the stock caddy mounts in my truck and welded up a flat plate on the frame for them to mount to.
The later (early '80's) 425 cars had the same chassis as the Caprice. If you find the mounts off of the 425 they'll allow you to drop the 500 wherever a SBC was. I used them on my '71 3/4 ton and it was a beast. Actually weighed in at 9800 GVW on a dump run. Cad motor wasn't even straining.
Well these are the mounts. You use the 2.8L V6 rubber mounts, that bolt to the frame, then these go onto the V6 mounts.
Oh, I could get a Ford Explorer 8.8 rear end, and put Crown Vic gears in it, the police package had 2.76. Would that work?
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