What engine would have been in this? A Chrysler Industrial Engine?
The standard power train would have been a Chrysler 318 Industrial Engine and a New Process 435 four-speed, or a New Process 540 five-speed manual transmission.
Note I said "Industrial". I believe Tucker bought the engines and transmissions as a package from Chrysler. The Industrial engine has some internal differences from the automotive counterpart, and those differences continue through the clutch, bellhousing and the way the engine and transmission mount to the Tucker. The factory installed the hydraulic pump on the right side of the engine with a Tucker made bracket system. The water pump inlet is on the left side on the 318 Industrial and on the right side on automotive engines starting in 1971 (IIRC).
The engine mounts to the Tucker frame with a casting that bolts to the front of the engine and has a single stud that attaches to the Tucker frame. The location is offset to the left of center. (I think this is due to the large diameter of the hydraulic pump pulley.)
Whereas typically automotive transmissions use a bracket in the rear of the transmission that bolts to a frame crossmember, the system employed in the Chrysler Industrial package is different. The bellhousing is a steel casting and has "ears" cast on each side. These ears have a hole in them and that is for a special bolt that mounts to brackets welded to the Tucker frame.
A couple other differences that come to mind are the parking brake system is essentially a drum that attaches to the transmission output shaft yoke and there is a linkage mechanism and cable that connects to the parking brake lever next to the driver's seat.
The clutch (IIRC) is 13" in diameter and is actuated by a slave cylinder on the right side of the transmission.
Tucker modified the stock oil pan by adding a few inches to the rear sump, This would also require modifying the oil pump pickup tube and possibly the pickup tube's mounting. They also added another oil drain plug to the oil pan welded off center to the right.
Some pics will help:
This is a photo of the engine mounting location. You can see the hole I mentioned is offset, and the hydraulic pump and pulley are to the left. I do not know if the pulley system on the automotive engines is the same as on the industrial engines. I do know that the hydraulic pump and the alternator used dual groove pulleys, and my suspicion is automotive alternators just use a single groove pulley.
This is a photo of the clutch slave cylinder setup. Note the throw-out fork has a hole for the adjustable linkage rod. Also, below the rubber boot are the ears I mentioned.
Here's a photo of a NP 540 transmission with the parking brake drum assembly on a machine we were making a new floor for. Note there is also a short driveshaft to connect to the transfer case. If you look closely you can see the parking brake cable running from the actuating lever around the front of the transmission and back to the linkage for the parking brake drum.
Lastly, the modified oil pan.
