VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 1935 - 36 heads

Please advise the difference between head castings;
837981
601988

Thanks, Joe

Hi Joe,

837981 is the casting number for all 1936 heads and was used as a replacement for 1935 heads:

http://clubs.hemmings.com/chevytalk/GMhistory/1916-57cast.html

601988 is the part number for 1935-1936 heads which have casting number 837981:

http://www.gmpartswiki.com/getpage?pageid=121478

So, I guess the upshot is, there is no difference. One is a part number, the other a casting number.

Happy Motoring,

Dan

the 1936 heads had larger ports than 1935?

Not that I know of...both heads are the same...both have the water jet spray nozzles.

Teh 1936 head combustion chamber was completely revised. Also The compression ratio was raised from 5.6 to 1 to 6.0 to 1.
The 1936 head became the replacement for the 1935 head after 1936. There were two differen heads used in 1935. The early 1935 Standard used a version of the 1934 Master head. The late Standard used the 1935 Master head. The 1936 head was used on the 1935 special ecomomy engines. The early 1935 head had 45 Deg. exhaust valve seat. The late had 30 Deg. The late used a different head gasket.
1936 engine all used the smaller port intake port intake manifold wich was also used on all 1935 Standards. This was done to increase low speed torque and limit high speed engine operation.(revs)

Thanks!

Looking at the exhaust manifold it looks like 837806 or 306 I cant decipher. Is the 837232 from the Master an upgrade with the larger ports?

The 1934-1936 exhaust manifolds were the same. The 1934 had a slightly doifferent heat riser valve but other than that the size never changed.

Thanks, I never knew a difference. Just a country boy. If it fit on there and ran; we used it. We did whatever it took to make them run.

I thought there is port size difference between the standard and master although they do fit any 34-36 aplication.

The 1935 Standard intake manifold had smaller ports....that manifold was then used on all 1936 engines.
Thats why the 1935 Std. had 74 HP and the Master had 80 HP.
The 1936 engine had the smaller ports but the new combustion chamber and higher compression brought the HP up to 79.

I own a '35 Std and have owned it for 38 years. About 23 years
ago I thought I blew a head gasket, so I pulled the head and sent it out to get checked;it turned out to be a cracked head, so I
purchased a NOS '36 head and sent it out to the machine shop to have hardened valve seats installed. It mated up perfectly with
my head gasket and I also replaced the intake and exhaust manifolds with a good used unit I bought at a flea market because
my heat riser was screwed up. I didn't know it at the tine,but
the intake was from a master. The car has more power now than
ever before, and due the improved cooling it runs cooler than
ever! Phil Lipton

What are the casting numbers for the better 36 head and intake?

837981 is the casting number of a 1936 head. The intake is 837595.

Thank you