Technical help me find what these motor mounts fit? 37 - 54 Chevrolet??

cleaning up 28 years of parts from my shop. I've got these brackets I am pretty sure are for putting a motor in something. I used to sell 1937 to 1954 Chevrolet parts on ebay so I am pretty sure these were from one of those cars. need help finding them a new home.

thanks in advance.

 

55-59 chevy truck, with v8 engine.

https://www.classicindustries.com/product/556038.html

for example. They bolt to the frame, or were riveted if the truck was factory equipped with V8.

 

thanks!! I never had one of those, must have been in a load of older parts I picked up.