Strange suffix code/

[mikematthews]

Hey guys and gals, I just purchased a 85 chev 4x4 K10 for intimidating people here in ND.Well anyway i was putting a new alt in tonight and noticed the block was stamped with a wierd suffix code on the right deck and was wondering if anyone can help. The code reads MO328OVP where did this thing come from?

 

[Firepower354]

Looks to be March 28, 1990(?) replacement engine from the Mexico plant. The casting numbers might take a little headstanding and some degreasing to see, but that would narrow it down.