Originally Posted by Brad_SwiftFur
That sounds like one of those old so-called "V-6 Detroits", as GM commonly used Detroit Diesel engines (it was a subsidiary of GM, as was Allison Automatic). They were 2-stroke engines and originally could be built for rotation in either direction, but to change one after manufacture requires changing a few internal parts (for example, the oil pump would run in reverse as well). They were considered very durable engines. There was only one potential thing, if it ever blew bearings/seals on the supercharger, then engine could "run away", burning the oil that was supposed to be lubricating the bearings. Many had emergency shut-offs that simply blocked air going into the engine just for this reason.
Wrong engine Brad! These engines had nothing in common with the -53 series or the -71 series Detroit Diesel 2-cycle heavy duty diesel engines.
The 432 gas V-6 was one of a family of engines that GM brought out in the early '60's. The baby of the family, the 305, was put in a lot of half ton through 1-ton GMC trucks from about 1960 to 1974 and the larger ones put into medium duty trucks up through some Class 5/6 trucks. I have seen quite a few 10-wheel dump trucks that had the 702 V-6's in them.
GM also made a diesel version of the same engine and called it the ToroFlow or Turbium Diesel engine. Regardless of what it was called it was a real dog.
The difference between the gas and the diesel engines were the gas engines had spark plugs and the diesel engines had injectors. Both the spark plugs and injectors were in the upper side of the head down in the valley.
I have no experience with the 432 but I have had a lot of experience with the 305, 401, and 478. I would imagine the experience I have had with the others would apply to the 432.
The engines all had an extremely narrow power band that came in around 2600 RPM and was gone by about 3000 RPM. Any slower and you ran the real risk of sucking the head gaskets out and any faster all you were doing was making more noise and using more fuel.
Most of them had overheating issues that had nothing to do with the size and efficiency of the radiator. The basic design of a LOT of cast steel and poor water jacket design tended to make them run hot.
Most of them, even after getting them blue printed and balanced still would shake the pieces off of them. I can't tell you how many carbs got tossed due to cracks in the bases where the throttle plates pivoted. Very few didn't end up having ears braised back onto intake manifolds, alternator and power steering pump brackets repaired, and air compressor mounts rebuilt.
As far as fuel economy was concerned, the IHC LV478's always got 1-2 MPG better than the GM 478's.
The IHC LV478's could be loaded up with the football team and motor down the road at 60 MPH. The GM 478's with the same rear gears and transmission loaded with the same team were hard pressed to keep up on the flat and at the first hill would need to drop a gear.
By the late '80's parts and pieces for the big V-6 were getting pretty difficult to find. I can't imagine what it would be like to have to find some of the V-6 specific parts now. It may require some very good sleuthing to find parts used in other GM engines that might fit or could be made to fit.
Good luck and Happy Trails to you!