The Stovebolt Site Forums The Shop Area General Truck Talk Higher rear end gears or Overdrive??

I would like to get a little more speed out of my '55 second series with the 235 six. What do you guys think would be the smarter way to go. A period correct three speed with the overdrive or a set of higher rear end gears?

Thanks!
Andy

I went with the overdrive myself. Keeps the performance of the lower rear gear (3.90) but still cruises just fine when od is engaged.

i live in realtivly flat indiana and i have 2.73 nova rear with 215/75/15 tires and it does just fine around here. ron BTW go to www.randysringandpinion.com and play with their calculator.

I like the idea of an overdrive. Best of both worlds... a true Win/Win situation.

Do you pull a trailer or carry heavy loads? If you do you need the lower gears so you probably want an overdrive. Otherwise you'll probably be find with changing the rear gears to something about 3 to 1.

Why not go with the best of both worlds...a T-5 OD tranny and 3.55 rear end?

actually the gears available for the TF rear are 3.38 .... fine for fairly flat country and light loads, but a lot more spendy than finding an original OD 3spd or even updating to a 4spd with an OD 4th

Bill

You can answer that question yourself with this
http://www.drivetraindirect.com/t_gear_calculator.htm
And the knowledge of how you want to drive and use your truck considering the capabilities of the engine and at what RPM.

First know what your choices are as far as gears and transmission ratios, then guess and check with the calculator till you find a combo that suits.

Grigg

I went with the overdrive transmission in my 53 and a 3.90 rear end. This gives me a 2.73 final gear in o.d. on the highway. Getting over 20 mpg. Couldn't be happyer.
Tom

What do you guys think is a fair price for an original overdrive trans? I posted a wanted ad on this site, but the only reply I've gotten is for one that is $350 plus shipping from Texas to Wisconsin. It needs to be gone through yet too.

Altough I have a different setup in my 55 2nd series,A 350 cu.in.V/8.I kept the stock 3:90 rear and put in a 700R4 OD tranny.I now have the best of both worlds ,plenty of power off of the line and it cruises at 65 to 75 MPH.Also gets 20 MPG.Same thing should apply to your inline 6.Maybe a T5 OD tranny and your stock gears.

Keep looking, they are tough to find but I have seen them as low as $75(basic trans,no cable/wiring, unknown cond, but rolls thru gears)at the swap meet. Swap meet season is coming up, hit a few & see.

I've seen TF OD's on e-bay regulrly, usually go for $1-2 hundred. 350 is a bit high unless it's guarenteed good

Bill

Thanks. I'm trying to stay away from modernizing the truck at all. It is a very nice original truck. I'll just keep my eyes open for a trans at the area swap meets. Will I have to shorten the drive shaft at all?

Thanks again guys!

no - direct bolt in swap and lots of info here regarding setting up the controls

Bill

I have owned several vehicles with the 3 speed and o.d. trans. No question it is the absolute best combination you could ever have in any vehicle. Definitely go with the o.d., you will love it, guaranteed.

Be aware that there are different OD's used in GM vehicles. The early one (55-65) has a 4 bolt side cover and will match up with your stock application. The later type 66-69 (7 bolt side cover)is a Saganaw full syncro trans w/OD and is very desireable. It will require a fine spline yoke and some shift arm tweaking. It is also more rare and usually priced accordingly. Either one will make a big improvement in the driveability of this old iron.
Fred

I've bought 2 of them, one from a '55 wagon, the other from a '57 Power Pack convertible. the first one was $150, the second was $100.
Seems to be the average price in this area for one.

I put myself in debt and went with the Gear Vendors unit. I have 7 gears including the granny with my original 3:90 posi rear. It truly gives me the best of both worlds. I can run 80 mph at 2800 rpm in 4th over which is the same rpm as 60mph in 4th. One day I want to pull an airstream around the country. I believe this tranny combo with a beefed up 261 will be just the ticket.

The idea of an overdrive interests me for a 1948 two ton. I am a newbie and was wondering if they are available. Is it an add on unit or a totally different tranny?

Super55 if you have a two ton you have the perfect reason to use a auxiliary tranny. I put a three speed brownie in a 47 1.5 ton project I'm working on and it works great. The brownie has under direct and over. In the over drive gear this makes 50 to 65 mph easy with the stock rear end.

I like the T-5. It gives you close ratio gears. I put a 4 speed gearshift lever on it & it looks like an original 4 speed.