54 Passenger Car Engines with manual transmissions had solid lifters.
Read under Tappets, Hydraulic valve lifters --- None.
http://chevy.oldcarmanualproject.com/chevyresto/5435.htm

54 Passenger Engines with RPO 313 (Powerglide transmissions) had Hydraulic valve lifters.
Automatic transmission option, Hydraulic valve lifters
http://chevy.oldcarmanualproject.com/chevyresto/5448.htm

Those Hydraulic valve lifters engine blocks have oil passages drilled into the block to feed oil to the Hydraulic valve lifters.
Where as the engines that had solid lifters did not have the drilled oil passages.

I believe the benefits of Hydraulic valve lifters is to maintain zero valve clearance and the engine runs quieter.
Conventional solid valve lifters require regular adjusting.

I would say the reason GM used hydraulic lifter engines with the powerglide transmission was because it added more luxury.
If you forked out the money for a powerglide transmission you got more than just a automatic shifting transmission,
A. Less engine noise in the passenger compartment.
B. Less engine maintenance.

What was the reason why you pulled it out of the 1941 Chevy AK ?
If the block is still good it would a good engine to rebuild.

1954 Chevrolet 3105 Deluxe Panel Truck
w/Factory HYDRA-MATIC