Looking at a 1983 GMC w/ a cadillac 500 motor

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87ChevyR10

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Looking at getting another squarebody. This one has a caddy 500 engine mated to a 700r4 transmission. Truck is very clean all around. However, the heater isn't hooked up. The climate controls and blower motor are still installed, but I don't know if they actually work. The guy I'm talking isn't local and will be looking into this further tomorrow. I should know then if the blower works and if the heater core is still there. If so, aside from hoses, what will need to be done to get heater fuller operational? I am unfamiliar with the cadillac 500 motor. It has an edelbrock carb w/ electric choke sitting on the intake. I'm rally hoping this won't be a big deal to resolve.

I would appreciate any insight on this. Thanks!
 

GMFORLIFE

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500 cadillac is a great engine.
Vintage air kit is about $1000 and includes new compressor.
They may have had to remove the stock ac components to get the engine to fit.

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Matt69olds

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There is no way a 700 will reliably handle the torque of a 500 Cadillac without some pretty expensive upgrades. I’m a Olds fanatic, Olds engines are well know as torque monster engines, there is no comparison. The 500 Cadillac sets the standard to which low end torque is defined!!!

If the Cadillac engine has the compressor mounting brackets, I would think you could install the correct compressor and have hoses made to fit. The vacuum supply line doesn’t care what engine is supplying the vacuum. You might need a heater control shut off valve to fit the Cadillac engine, once again that should be a big deal
 
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Powerhouse Ranch

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500 cadillac is a great engine.
Vintage air kit is about $1000 and includes new compressor.
They may have had to remove the stock ac components to get the engine to fit.

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HELL YESSS!
 

Matt69olds

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I just re-read the original post, is this a truck with heat only? If so, I can’t imagine any clearance issues with the Cadillac engine.

Since someone posted vintage air info, I assumed this truck had air conditioning.
 

1olddog

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You will have to drill and tap for a fitting for one of your heater hoses. There is a place on the right front below the thermostat housing, 472/500 Cadillac heater hose was in the back of the right side head,doubt you will have the room to use it. The other heater hose comes from the radiator on the right side.
 

Raider L

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@87ChevyR10,

Don't know much about Cadillac engines other than racers used to use them back in the sixties with great success, and the big blocks were some of the first 500 cubic inch engines. There was a Lincoln continental engine back then that was either very near five hundred inches or right at it and could haul butt.
The other thing is to make sure all those vacuum pots are working and that the vacuum manifold behind the dash controls is not defective, and all those clear rubber hoses that go to all the a/c doors are good. That is if you are keeping your original air and heat controls and system. I know I have a couple of pots that are dead that control the door in the valance and the kick panel so I can get my "vent" setting to work. Even though I removed my A/C decades ago I still have the control for the doors, that when I set it on A/C the door opens and it blows cool air. Amazing, huh? Ghost a/c.

@87ChevyR10, @1olddog, said there was a port in the back of the right side head. Yeah, there should be a way to the water jacket there like the Chevy 350. If that's the case, @87ChevyR10, what's in that hole? Did someone plug it? If so could you put a hose fitting like found on the front of 350's that comes from the heater core, there?
 
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GMFORLIFE

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Not sure if the 500 ever came in a rear wheel drive car.
Every 500 powered car I've owned was in a front wheel drive Eldorado.
Great in the winter!
Could always bolt a tremec on that beast..lmfao
 

CorvairGeek

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Not sure if the 500 ever came in a rear wheel drive car.
Every 500 powered car I've owned was in a front wheel drive Eldorado.
Great in the winter!
Could always bolt a tremec on that beast..lmfao
Standard for DeVilles from '75 - '76, but available eariler, IIRC. Be aware that the Cadillac 368, 425, 472 and 500 are all the same engine family. It could be easy for someone to mistake (knowingly and unknowingly) a smaller displacement for a 500, especially after a swap.
 

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