Not much difference really, the 76A being older and all used the D333T.
The 10K started out with the D333 and switched to 3306 at sr. #7953 and sleeve metering at sr. #10056
There were about twice as many 10K units made than the 76A.
Hi JB
I think the 76A was 120 Hp and then they changed to a Naturally Aspirated D333 which was 125 Hp, then the later 10Ks had a smaller turbo and were 140 Hp. Not sure what they are worth now.
Cheers, Dave