i just pulled the eprom assembly from my 1991 chevy 1ton truck (note this has a 4L80e tranny) and the prom looks nothing like the unit out of my 88 truck which has a 747ecm. this ecm# is 16147060. the prom i pulled out of the ecm is imbedded into a plastic housing with other chips and has 66pins on it! i thought all 1991 trucks have 24 pin eproms. the eprom on this plastic housing has 28 pins and they look to be sodered into this holder. THE TRUCK IS A 1TON 4X4 C/W TBI 350. what is going on here can anyone help?

FORGOT TO MENTION: the sticker on the eprom says delco 9107 and the cover which goes over the plastic assembly says: awbp 4349

the eprom is takes up one end of the holder and at the other is 2 chips under another clear coated prom assembly which you can see all the circuits. the whole plastic assembly is clipped into the ecm by plastic tabs on each end and the plastic cover is light blue. i am lost!

i think i found my answer to my question, MEMCAL!!!!! RIGHT!!!, what the heck is this doing in my 1991 truck?