drive shaft length

[snipescastle2]

Hi everyone! Can anyone give me the correct length of a shortbed driveshaft (one piece) from the end of the slip yoke (TH 350) to the center of the U Joint bearing cap? I sure thought I'd end up cutting my driveshaft, running a 700R4, but my drive shaft is roughly two inches too short, maybe 1 1/2" of the yoke in the tailshaft of the trans. and currently, this is the bare chassis, no body weight on the suspension, I figure it would only get worse with the added weight, with regards to chassis droop.....any ideas?
Thanks!
Ben Smith