VCCA Home Forums TECHNICAL - GENERAL Trucks and Vans block and head cstg numbers

I have '34 1/2 ton with a rebuilt engine I don't know by whom or when, but it had never been run when I put it in my truck. I was told it was the original engine for the truck. The numbers on the engine are A-17-5 and 837591-4. The head was cracked so I bought a NOS one the number on the head is 837891. It is overheating and I have checked everything. What next are the block and head compatible and how do I know if I have the correct gasket?

A-17-5 is Jan. 17th 1935. The cylinder head casting number is
837981.

837591 is a 1935 engine block and it is not the original engine for your truck.

I can't find 837891 as a casting number for a cylinder head, however if the casting number is actually 837981 instead, then the cylinder head is 1936 but it is also a replacement cylinder head for 1935.

If a 1934 head gasket was used for the 1935 block and head you have that could be your problem as some of the water passages would be blocked off.

The 1934 head gasket fits a 1934 Master and an ealy 1935 Standard only.Also fits 1934 trucks.

The 1935 Master and late Standard and all 1936 models use a different head gasket.

It will be necessary to remove the head and inspect.

Also the water pump will fit a 1935 block only.

edw47,
'34 and '35 trucks are pretty much alike except for the engine. Do you have an I.D. tag on your truck? 1934 I.D. number should include the letters DB. 1935 I.D. number would include the letters EB. 1934 keys are double cut (teeth cut on both edges). 1935 keys should be cut on one side only.

Mike

Thanks, good info. Head is 837981, I transposed the numbers. looking at pictures from the Filling Station I think I have a 34 water pump. I'm going to change it to a '35 and check the head gasket.

If a 1935 water pump only fits a 1935 block what is the difference? What happens when a '34 pump is used on a '35 block?

The 1935 water pump impeller is larger than a 1934, smaller than a 1936. Lower hose connection is larger than the top hose, 1 1/4 VS 1 1/2". Also the 1935 has a tapped hole for a heater hose connection, the 1934 does not. The baffle in the block (make sure it is installed) is larger for 1935 (not used in 1936)
To be honest I don't think the 34 will fit a 35 block.....but make sure the metal baffle is pressed into the block behind the water pump. If needed is available from the flling station.

I did that once...put a '37 on a '36....ran hot until I went with a '36 on a '36. These years.... they were improving each year. That is why one year won't fit on the other.