OK so this is pretty specific and I had to look through 4 pages of u-joints after narrowing down by engine/transmission and body style. Yet there were even more options.
I'm making assumptions at this point, as quadrasteer isn't that common and since you said you have a short bed, you should have a 1 piece aluminum drive shaft. This would probably be easier by VIN but...
Try this it's a NAPA part number, SKF brand. Should be easy to do an interchange on the number.
UJS UJ534G This looks like it's used for the front and rear my vision got blurry around page 3 so you're probably going to have to measure the outer diameter of the bearing cap on the u-joint.
w/ Extended Cab;w/ Automatic Transmission;w/ Regular Cab;w/ Standard
Bearing Cap O.D. 1 : 1.125"
Construction : ISR (Inside Retained)
Inside Lock Up 1 : 2.557"
Lube Fitting Location : In Cross
Series : Mechanics 3
Style : 4 Grooved Round Bearings
Here's one from a different manufacturer with a nifty measuring diagram
Body Styles : Pickup (Ext'd Cab 4 Dr.) Comments: Front Shaft Front And
Rear Joint;w/ Standard Bed;Non-Greasable Per Car Qty: 2
Bearing Cap Diameter : 1.125"
Bearing Plate Diameter : N/A
Bolt Hole Circle Diameter : N/A
Cross Dimensions : N/A
Fits Driveline Series : SPL25 / S44
Greasable : No
Outside Snap Ring U-Joint Cross Trunnion Diameter : N/A
Outside Snap Ring U-Joint Overall Cross Length : N/A
Snap Ring Dimension : 2.556"
Snap Ring Inside
U-Joint Cross Trunnion Diameter : N/A
U-Joint Bearing Type : Inside Snap Ring
U-Joint End Yoke Dimensions : N/A
Contents : U-Joint, Caps & Snap Rings
UNSPSC : 25173810
As to the other questions
Does anyone have a good reference or a good way to tell how to which
U-Joint is needed for any given application?
Maybe something exists to make this easier but I'm still stuck in the past when it comes to looking up parts. Most trucks have far too many options for this to ever be easy.
For example on this truck you need to know
- The size of the bed standard/long
- The size of the cab
- Which transmission style automatic/manual?
- Which Transmission 4l60e/5lm60?
- 4WD or 2WD?
- Does the truck have Quadrasteer?
- Is the driveshaft aluminum or steel?
- How many sections on the driveshaft?
- Depending on previous configurations which u-joint front, rear or
I'm sure I missed an option or two here...
Is there a specific way to measure them which allows a person to find
them easily or to match them to what is needed?
See attached diagram.
Do auto makers tend to stay with one size across their product lines?
In my experience... No.