[dsraven]

seems like the perfect time to upgrade to more speeds and possibly an overdrive, unless you are building to keep it stock. an open driveline would simplify and update things plus you could pick a gearbox and axle ratio that would help on the take off's and possibly keep engine rpm's reasonable while cruising down the highway. I understand there are likely a few of the old transmissions out there but you are still talking about an old used transmission which has seen many years of use or may need a rebuild, old used shifter mechanism, torque tube, driveline etc etc. there is always the "while I have it apart" scenario that we are all familiar with and usually ends up with a full rebuild of the old stuff and then, in the end, we still have a truck that is sorta high geared in first for taking off and tops out quickly on the highway. it may be worth the time and effort to research the costs of redoing the old compared to upgrading. I know, anything other than a 3 on the tree is gonna be more work and will end up with the shifter located on the floor, but the choice is yours. just saying to look at your options and check ALL your old parts for wear etc. I don't know what you have, how you want to build it or how you like to drive it so i am just saying look at your options and costs to do different things. a full syncro trans would certainly be a nice option.