No casting info????

Dartnut said
Hydraulic lifters started for the 1980 model year.

No, 1980 was the last year for solid lifters and 1981 the first year for hydraulic lifters (except for an unusually large production test run of hydro-lifter Slant-6s during the 1978 model year).

Another easy way to tell a 170 or 198 from a 225 without looking at the numbers is to look where the water pump and head outlets are. The short deck (G engines) have a very short hose connecting them while a 225 (RG engine) has a longer hose to connect them.

Not quite. The 170 is the LG (low G) block. The 198 and 225 both use the RG (raised G) block, so the 198 and 225 have the same longer bypass hose; only the 170 has the shorter one.