I've tried searching a bunch of websites but haven't been able to ID these two motors.
The 1st is a 235 in my 57 GMC 9300. Casting number 54738. It has a rebuilt tag from 1968. From prairie remanufacturing in Winnipeg. Tag says motor number SG235 1679.

The 2nd motor is one I picked up for parts. It was in a 57 Chev 1/2 ton. Casting number is C216381. This one has hydraulic lifters so I expect it came out of a car originally.

Thanks in advance.

Ok, I�m a little smarter now. Understanding the difference between engine ID or VIN and the casting number. Found the casting number
On the motor in my truck. 3836233. So it�s a 55-57 235. Got that from this site. It has some great info.
http://devestechnet.com/Home/CastingNumbers

Glad you found what you needed. Thanks for posting the link. That should be added to our "casting numbers". Most of our links there no longer work.

Took a while to find the casting number on the 2nd motor. It was behind the starter. 3837004. Cast number's page here says it's a 1956 235. The head is 3836848, a 235 number.

Tim's Lederman's site says a 1956 car 235
http://www.1954advance-design.com/Stovebolt-engine/casting-numbers.html

The link on his site to Canadian GM says 3837004 Chevrolet T56X 55-57 235-261
Anyone know what a T56X is ??
http://home.znet.com/c1937/Cast.htm

Hi Sparky77 . . . glad to see you digging in and doing some research. There is alot of resources online, but it takes time sort through and make sense of it.

First things first, Canadian GMC (light trucks) never shipped with GMC engines - they got Chevrolet engines. So the 235's you have encountered are correct for the application. A GMC 9300 in Canada is essentially a US Chevrolet 3100 with GMC branding.

The other thing to keep in mind is that you are on the cusp of a transition period. A '55 1st Series Truck had a block with small cam-journals (introduced in the '53 Corvette complete with solid lifters). Second series '55 Trucks came with the new larger cam journal block casting. And that 3836848 head will fit on either.

The GM Parts Wiki is the place to search:
Fitted Block: Parts & Accesories Catalog November 1962
but it can be frustrating - as not all production casting numbers or parts numbers were referenced in print. Keep in mind these are Service Parts catalogs. Many parts were used in initial production but never placed in inventory (and therefore cataloged) as replacement parts.

As for the T56X - that's a 235 built in Tonawanda "T" in '56 for a 3100 truck "X". See attached.

regards,
stock49

Thanks Stock49, that was very helpful