To ID a 5 speed first
go here for a visual ID then go check
5-speeds to narrow it down. You are looking for an early to mid-80s S10 trans from a V6 truck. Astro Vans are a possibilty too. Later V6 S10s will fit but have electronic spedometers.
Check out the trans by shifting through the gears to see if everything moves smoothly. Rotate the input shaft and check for any grinding or binding. You can SWAG the ratios by counting number of rotations of the output shaft vs turns of the input shaft in first thru 5th. Try to stay near your stock 1st gear ratio. Look for a .70 - .73 5th gear. There may well be a list of T5 internal ratios somewhere on the web, if you have time to wade through all the Mustang and Jeep stuff.
As far as placement of shifter...The base of the S10 shifter is 12" back from the bellhousing flange surface. Remove your floor pan cover and measure your stock tranny. The shift knob in 2nd & 4th gear is about 11" back from the shifter base with a Hurst S10 shifter - I don't know about the stock shifter.
