You would need to lock one tire & turn the other wheel one full revolution,then multiply how many times the driveshaft turned by 2. So,if you counted the driveshaft turns a little over 1 & 1/2 turns,you would multiply that by 2 which will be 3.08s
If you want any advantage & give your dad a run for his money,you'll need to gear all the gearing advantage as you can get. A T-5 trans will give you better take off than any muncie.
There are some Saganaws w/a low first gear, but no overdrive.
You should be able to find a used T-5 in junkyards,or Craigslist or friends or?
Any other trans are going to cost you some $$$ like a doug nash 5 speed (think they have a new name now?) T-56 6 speed .50 OD? which would need an efi to use 6th gear unless you had like 4:88's Just off the top of my head,so not too accurate,but I think close enough?
