Determining TH350 length

[RaptorSentry]

Without having to get underneath and measuring the transmission, since I am in different state right now than my truck, is there a way to determine if I have the short or long version of the TH350 transmission?

My guess is I have the short version, because I have a K20 and the transmission sits between the 350 motor and the transfer case.

Reason why I ask is I would like to put a transmission with an overdrive in, without having to invest in a new front or rear driveshafts due to having to move the transfer case location if the new transmission would be too short or long than the TH350 that I have in there now.

My understanding is if it is the short version of the TH350 the 200R4 would be the best replacement. While if i have the long version of the TH350 the 700R4 would be better transmission to go with.

What are your thoughts? I know I'm probably missing something.