1981 Chevy SWB C10, 5.3L 4L60E

[CHIEFWAHO]

1981 Chevy SWB C10 2WD, 5.3L 4L60E

Have owned the old truck since the mid 80’s. Drove it all thru high school.
Has set the last few years as the 305ci with turbo 350 just guzzles too much gas.

Picked up a 2WD, 5.3L (DBC), 4L60E combo it’s supposed to be from a 2003 Tahoe with 56K miles.
The combo was already pulled when I bought it.
The VIN (1GNEK13ZX2J301248) provided after the purchase shows it being a 2002 4WD Tahoe.

So I need some help determining what year the combo may be?
Here is information I have from block, heads and transmission.

Block
Passenger front block G04
Driver rear stamp/cast 12551358
Dot Matrix CYZ128778
Passenger rear side Sticker FHB (big letters) 10FHBW991765040
Heads
‘862’
Driver front Dot Matrix 9917418163739864
Driver rear Dot Matrix 9174T3858865
Driver rear sticker FHB (big letters) 10FHBW991765040
Passenger rear Dot Matrix 9917418163639664
Driver rear Dot Matrix 9174T3848865
Transmission
Sticker: 24202741 610CCDY27621305 OOCD
Dot Matrix CYE399253



Engine tranny combo


Parts stock pile: gas tanks, headers, misc


Started stripping her down


Labeled the harness during removal