vt1214, vt1414, sr1700

I have a 1996 Volvo WIA with a vt1414(sr1700) transmission. First gear in the transmission is bad so I started to look for a used transmission. Found one at a local wrecker and brought it home. After doing some looking at the two transmissions I noticed some differences in the transmissions like the yoke for the driveshaft is smaller and is splined to the output shaft on the salvage transmission and my original trans has a flange the yoke is bolted to. I took the part number (1653163) from the transmission tag and contacted the Volvo dealer. He found out the transmission is a vt1214. Can anyone tell me will this transmission work in my application? What is the difference between a vt1214 and a vt1414. What does the sr1700 designation mean, because both transmissions are marked as an sr1700.