472 cadillac engine swap

[jwcummings]

Ok I have a 1984 c20 cab sitting on a 1981 k20 frame, with a 1974 350 mated to a th400 and np208. I have a chance to buy a 472 cadillac engine that needs to be rebuild and I am trying to figure out if it would be worth the process of rebuilding the engine and swapping it in to the teuck. I have read that the 472 is a torque monster. I have looked into doing an ls swap but I hate computers due to my lack of knowledge of computer controlled cars.

 

[CSFJ]

The caddy engines are torque monsters. Have you priced the rebuild parts and machine work yet? Last I heard the caddy engines were kinda pricey to rebuild.

 

[350runner]

Heck yea go for it!

 

[hirschdalechevy]

Cool swap , but I dont think the tranny will bolt up ,(from memory) , you might want to check into it , I know there is a way to make it work though.Way back I had a wheeling buddy that had a 500 cad in his 74 square but I cant recall what the deal was but it got with the program , (I do remember that).

 

[Green79Scottsdale]

Cool swap indeed! IIRC, these big engines weigh about the same as a small block. Big power in a relatively light package. Aftermarket EFI would be really cool on it! Yes, I know the OP is thinking carb.

 

[1984dually]

cad engine

Of all the engines I have run in my 84 Dually the Cad 500 that I swapped into it is the one I will never do again. Engine was a 1970 Eldorado 400 hp After building my own mounts and using a bop cased th400 it over heated first time I put a load on it. Had a big radiator in it but installed a new one before taking off on Vac to Reno and Southern Ca. Was pulling an open trailer with a 66 Belair body. Fought overheating issues for the whole trip. Changed thermostats/left it out/added electric fan at the pepboys on Hollywood blvd. Nothing helped. Stopped at every water stop coming over the Grapevine coming out of LA. Changed the rad to a diesel one when we got back. Didn't change a thing. Did some other mods to address the problem but always the same. Every time I hit any hill it got hot. 26lb cap was the only thing that kept it from shoving the water out( even that didn't help sometimes) Street Rodder did a Cad build a few years ago and they almost cooked it on the dyno. Got so hot the exhaust was red. Since found out that them engines had a heating problem from day one and Cad new it. 26 lb caps/temp light came on a 265 degrees/temp sensor to retard the timing at certain temp. Do I like Cad engines NO. For a car or truck that NEVER is loaded maybe. Anything but a Cadillac.
Sorry for the rant but that's my story and I'm sticking to it.

 

[Joe383]

Ya its worth it. A friend use to have a 500 in a 72 chevy 4X4 that was modified that was fast as hell. It had an edelbrock intake, comp magnum 270 cam ported heads, headers ect... I don't remember what carb be ran but it was a great truck. He dad to have headers and so the motor was too wide for the frame Had to notch the frame and weld 1/2" plate on the out side to reinforce the frame.

 

[cadpwrd]

I put a 500 in my truck and finally got it on the road last spring. Good power, torque to lend. I love it. I made my own mounts and used an adapter plate to mate it with my Chevy patterned TH400. I used the radiator from the donor car (75 deville), a 180 thermostat (the correct Caddy specific one), and a set of Derale electric fans. Ive run it hard, put 2500+ miles on it so far, and it hardly over goes over 190 using only one of the fans. It went to 205 once while sitting in traffic for 20 min on a 90 degree day, once i turned on the secondary fan, it dropped to 195.

 

[CSFJ]

I was just looking at this thread yesterday. Was wondering if there were any more people who had done this recently. Starting to think one of these monsters may end up under the hood of my '87. Even found one on c-list a couple hours from me.

 

[85c10owner]

Friend of mine did a 500" in his 76 stepside. I know he rebuilt it stock with a mild camshaft, performer intake, stock manifolds and a adaptor to work with a 700r4. Has tons of low end power. Not sure what he did for a radiator but you have ot remember that it takes more than a big radiator to cool any engine. Proper fan spacing, correct clutch if using a clutch fan, ect. I know they are light but probably cheaper to build a bbc and make similar power.

 

[80goldenburb]

cad engine

Of all the engines I have run in my 84 Dually the Cad 500 that I swapped into it is the one I will never do again. Engine was a 1970 Eldorado 400 hp After building my own mounts and using a bop cased th400 it over heated first time I put a load on it.

What "load" did u put on it? Ive owned two 76 cadillac devilles with the 500 and would rev them to 3900 at full throttle all the time for ***** and giggles.They NEVER overheated except when the water pump gasket blew. Yea mine were both low compression motors and yours is the higher 10:1 version. Did you use premium gas? Because 87 camel piss in ANY cadillac V8 from 68-70 will result in detonation esepcially in the dryer desert region near your state, which in turn builds up heat.

Had a big radiator in it but installed a new one before taking off on Vac to Reno and Southern Ca. Was pulling an open trailer with a 66 Belair body. Fought overheating issues for the whole trip. Changed thermostats/left it out/added electric fan at the pepboys on Hollywood blvd. Nothing helped. Stopped at every water stop coming over the Grapevine coming out of LA. Changed the rad to a diesel one when we got back. Didn't change a thing. Did some other mods to address the problem but always the same. Every time I hit any hill it got hot. 26lb cap was the only thing that kept it from shoving the water out( even that didn't help sometimes)

How hot was outside temperature? Detonation can occur when using inferior fuel in high comp engine in a hot environment especially when you work it with a load.

cad engine
Street Rodder did a Cad build a few years ago and they almost cooked it on the dyno. Got so hot the exhaust was red. Since found out that them engines had a heating problem from day one and Cad new it. 26 lb caps/temp light came on a 265 degrees/temp sensor to retard the timing at certain temp. Do I like Cad engines NO. For a car or truck that NEVER is loaded maybe. Anything but a Cadillac.
Sorry for the rant but that's my story and I'm sticking to it.

Um yea never heard of that, i thought street rodders were all chevy luvers. Cant seem to find this article your refering too, so ild have to see it to believe it. Theres nothing wrong with these engines except for the low redline. They are the same as the other BOP line of GM power plants when it comes to cooling and maintenance. You are the second person ive heard about an overheating issue while everyone from daily driven led sled rat rodders to turboed engines (with all the aftermarket goodies) race at the track are all fine and have no issues whatsoever. Just because YOUR specific motor had an issue from wahtever amatuer you bought it from doesnt mean they are all problematic. And its ironic i came across this thread because i just put a downpayment on a '70 eldo 500. Im dyin to have 535 lb ft torque over this rv boat anchor slug i currently have between the fenders.

 

[1984dually]

Been quite a few years since I ran the engine so bear with me. I rebuilt the engine with later pistons as the stock 70 high compression pistons were not available at the time(still have the old pistons somewhere). Ran all grades of gas and none made a difference. Weather was not a factor either as it would overheat under load every time. Not loaded(race car on trailer) it did just fine and even got good mileage(17 plus). Since the high heat light never came on until 265 in a stock caddy the issue of over heating most likely would never be a problem. Tried different timing curves and it didn't help. Was told once that I had the head gaskets reversed(cooling holes in gasket got bigger from front to rear to force water to the rear of the block). Pulled heads and gaskets were on correctly. Told I was turning the engine too high(3.73 gears in truck) wasn't. Cooling system wasn't totally the same as any other gm engine at the time. Return from the engine came out the front of the block in caddy's and not out the intake as in other gm engines(only one I can remember with a dry intake). To this day I think the problem was water staying in the rear of the block(water had to go into the block, up into the heads, and back into the block before going out to the radiator). Later engines moved the heater hose from the front to the rear of the cylinder heads. Thought about drilling the rear of the heads to force water to circulate thru the back of the engine but got tired of messing with it and put in another 454(now has a 2003 8.1L/4L80E) Cooling problem went away. Engine went into a 70 Pontiac Lemons and was drag raced as well as street driven. Drag racing is a short term load and never caused a overheating problem. The Street Rodder article was a year long build up of a 500 in Caddy engine(lots of high dollar parts). No where in the write up will you hear about the overheating. I talked to the guy doing it and that is how I found the info. Bottom line(as least for me) is if you are running a stock Caddy or have one in another vehicle overheating should not be a problem. Put it in a 1 ton dually pulling a trailer uphill and it will overheat.

 

[MikeB]

Cool swap indeed! IIRC, these big engines weigh about the same as a small block.

Wow! That surprises me. I'd would have guessed it was as heavy or heavier than a BBC. What did Cadillac do to save weight?

On another note, just about ANY engine with big cubes will be a torque monster, assuming you don't use a big cam. Except for the high performance versions, those giants were designed to make massive torque at 1500-3500 RPM to pull around heavy vehicles, and to heck with RPMs and peak horsepower. Sure would be lots easier to BOLT IN a 454, if you could find one to fit your budget.

 

[Green79Scottsdale]

Wow! That surprises me. I'd would have guessed it was as heavy or heaver than a BBC. What did Cadillac do to save weight?

On another note, just about ANY engine with big cubes will be a torque monster, assuming you don't use a big cam. Except for the high performance versions, those giants were designed to make massive torque at 1500-3500 RPM to pull around heavy vehicles, and to heck with RPMs and peak horsepower. Sure would be lots easier to BOLT IN a 454, if you could find one to fit your budget.

I remember Car Craft doing a build on a 500ci Caddy engine a long time ago. The weight, or lack thereof, surprised me too. IIRC, the thing made over 600 lbs/ft of torque with a pretty mild cam. My dad's cousin was building one several years ago. When I was talking to him about it he mentioned something about using Big Block rods and doing some DIY port work. Never heard if he finished though.

 

[shiftpro]

An aftermarket oil cooler (big one) with an inline thermostat (very important) will go a long way to help keep a big cubed torque monster happy. Also don't forget a big rad cooler, again with a thermostat. Both of thee components will help.
Have to think of the total package. There's more to keeping a big block cool. Need more than just a cool thermostat.