short Automatic Transmission Dipstick

[slowboy]

1972 GMC P/U Truck
CUSTOM 1500
350 4bbl
TH350 Transmission
REAR WHEEL DRIVE

I was checking transmission fluid and the last couple inches of the stick snapped off...the end that goes into transmission with the measurements on it.
Fortunately it broke off in my hand and not in the transmission.

While looking for a new dipstick I purchased one that I thought was right for the TH350, it said for GM TH350 on the packaging.[I think part number was 720-9764]
Only thing is, is that the new dipstick was [I returned it to Advance Auto until I can find out what's going on], 27" long from the tip to the top of the top hat, and the one I took out of my truck was only 24/25" long from the tip to the top of the top hat.
Can anybody tell me how my truck could possibly have a shorter transmission dipstick? And is this normal?
Could somebody apparently had put the wrong length dipstick in before I bought the truck?
Or is this truck known for some of them having the shorter length dipstick?

My understanding is that the TH350's pan is a square with a corner cut off... and that is the way my pan is and that's why I'm calling it a TH350.

Thanks and much appreciation for all info,

Keith [slowboy]