[Grim Reaper]

Ok my turn of what I remember.

The key years would be:
73-77 are pretty identical other then trim and colors and grill inserts.

In 78 you got th gas door and the door panels covered more door. Some stuff went electric like the oil pressure gage. In 78 there was a major electrical upgrade to the Blade style fuses. In 78 the rear seat passengers got a foot well and the rear seat became fold and tumble. In 80 Square headlight but still ahd the 73-80 fenders with vertical turn signal. In 80 or 81 electric choke.

81 new front clip with fixed cowel and truck lost weight with the lighter 208 aluminum transfer case, lighter built front clip, I hear that the gage of both body and frame was a little thinner. On a 4x4 the weight savings was around 340lb. It was about 200 on a 2wd truck. 305 made it's come back as well about 81. 700R4 overdive was a mid to late 81 addition as well.

87 was fisrt year of FI and only Year of FI in that body for the regular cab pickup. Crew cab, burb and K5 sontunied old bdy style through 91 to fufill goverment 10 eyar contracts to the Army that was signed in 81.
89 these trcuks got a cosmetic redew of the grill and interior. Re designated as the R for 2wd and V for 4wd in 88 to diferentiate from the new body.
in 90 they went to a tranny mounted VSS and electric speedo. in 91 the 4l80 showed up in the 3/4 and hlf ton varaints to replace the TH400.

4x4 stuff
The NP203's started in 73 and ran through 79. in 74 the NP203 was behind just about eveything including manuals. Pretty well the only year that was available. in 75 the NP203 was only behind manual transmission special order.

in 80 all trucks got a slip yoke 205 and 203 was discontinued. it carred a little into 81 and after that the 208 started.

241 replaced the 208 in mid 90.

about 83 the manual trucks went from Course 10 spline input to the stronger 40 spline input. about the same time they went to hydraulic clutch.

D44 was run through about 77 for front half ton trucks and then went to the 10 bolt front. in about 90 the to front went 30 spline.

D60 front showed up in 76. Before that you could NOT get a 1 ton 4x4. It simply did not exist.

The D60 was the first axle that could handle the 454 power and that was the first year you could get a 454 1 ton as well. Because the D60 was never installed in the Suburban you could not get a 4x4 454 powered burb in this body style EVER.

Think that has the big points.