Post detailed pictures or links to high resolution pictures or a video of what you have.

Greg

Turns out the T170 is a Tremec 4 speed transmission used in late 70's to mid 80's Ford trucks and some cars. It is like our 833OD. 4 gears with 4th being overdrive.

It looks like a possible swap job.

The 4-speed hump for the 833 /Hurst shifter is there, s it probably had an 833 at one time.

I saw a older dodge pickup with slant six 4 speed transmission (it has the round headlight) with granny gears. Could I rebuild it and change out the gearing so it picks up alot quicker just like the trans that I have in it now.

The usual practice is to start out in second gear with the granny-geared trucks. Second gear is just like the first gear in other transmissions, with the granny-low provided for heavy towing, pulling stumps, starting on steep hills and in agricultural work where it is used to ease along through the field at idle while loading hay bales, sugar beets, etc.. Often, children were the designated drivers when harvesting and sometimes, when straddling rows in a big field, no driver at all would be aboard until approaching the end of a row.
A granny-gear with a slant six will out-pull most anything on the road. As you might guess, I like them a lot. I wish I had one. If you go with one, no rebuilding except maybe seal replacement should be necessary. I've never heard of anyone wearing one out, or tearing one up.

would I also be able to use the same shifter I currently have?

No you would need more than just the transmission if you switch to the granny gear transmission. The Bellhousing, flywheel, clucth, pressure plate are all different, and would need replaced as a set. The shifter on those transmissions is built into the top of the transmission. Your driveline would need a different yoke...etc. Not even sure that the floor pan above the transmission may be different.

You are almost always better to find a complete set up from a donor truck if you are trying to make a swap. Do you want or need the granny gear? I hate them because you basically have a 3 speed with a low gear so low as to be unecessary 99% of the time. Do you want to be able to cruise on the highway and have a OD gear, then the 833 OD is probably the way to go and likely what your truck had originally.

Any way you look at it all this stuff is 40 years old now and half of it is worn out. Good luck finding what you are looking for.

Does the shifter hang off the side of the transmission or does it stick out of the top? 833OD have the shifter mounted onto the side of the tailshaft using an aluminum adapter bracket.

cruise on the highway with quick acceleration.