The Stovebolt Site Forums The Shop Area Driveline more gears

just wonder'in- many folks tell me how poor mileage I am going to get from my 305 V-6 61 GMC half ton. it is stock with the 4 speed floor shift trans. I have change gears in a ford 8.8" years ago. I am wondering if there is enough to be gained by trying to locate a good set of gears to swap out in the rear end- say down in low 3-1's? I am not planning on pulling it hard and expect the big engine can lug plenty good. not sure if slowing it down with gears so it would run more slow at highway speeds of say 65 to 70 max would be worth the cost. no doubt some after market sources out there that might supply them but interested in advice from experience.it won't be a primary driver and I'm kinda guessing I'd have to drive several thousand miles to regain the expense even though I can do the work myself.it currently has right around 4 to 1 likely 4,10? 2 WD 1000 series.

4.10 is a good ratio for an overdrive transmission.

A 4.10 is an excellent ratio for an OD like Cletis says and the 305 has the torque to pull it. However don't expect much fuel economy out of a V6. The fact that they were gas guzzlers is why they quit making them during the oil embargo when the price of gas doubled.

true- I hate to try to start swapping trany's and truly I expect it will not be driven enough to even justify the cost of rear gears. I was kinda thinking out loud in case I was to find a deal on a set- maybe used that would fit the housing. but if a bolt in O.D. trans could be had for reasonable enough bucks down the road I'd sure be interested. are there any that fit the bill? I have not checked into that possibility.I would like to know what options there are. I do kinda want to keep the old engine and third gear synchronizer is weak for sure.

As far as I know, one of these will bolt up and use the same driveshaft.