I will help with what I know. H, my 54 has a coolant petcock there. Actually, the hydramatic throttle return spring hooks around it. G is oil pressure connection. My engine has a T fitting there for oil to filter and oil pressure guage. F is where the linkage pivot goes for hydramatic linkage instead of the forward position where yours is for manual transmission linkage pivot. E I think may be oil drainback for oil filter. A,B,C,and D, I need help on. I am sure that some of them are for generator mounting bracket but I don't know which ones. Hope this helps a little bit.
