It's obviously a 198 and the BH you are showing in the other picture means it's one of the better casts, with the forged crank.
The build date is somehow coded in the 1595 or 1505 number and that's not clear.
Do you know what car it came out of ?
It is also very probable that the 4 is 1974 model year (K or 4 = 1974. The 198s were offered from 1970 to 1974).
Is there a dash after the 4 ? Not sure what the / is.
Try to do a little research based on what you know now.
Hope this helps
