The Stovebolt Site Forums The Shop Area Engine Shop school bus rear end swap

i have found a 60-62 school bus w/ a 4speed auto trans in it..if i use the trans and rear axle will this gear my truck up for highway speed?and is there a place for a pto on the auto trans...havent looked at this set up yet but plan to this weekend...im gonna use a 402 bb in a 56 6400...any help is appreciated

Hy 56chevyguy, if the tranny is stock to the truck, it will be a four speed Hydramatic, there is no provision for a p.t.o. on this tranny. This tranny does not have overdrive, the rear axle used with this transmission may have a lower ratio [numerically], and if it does, it will give more top speed, for any given input r.p.m., hope that helps

Its hard to imagine a Hydra-Matic being the right choice behind a 402, is that really what you are considering?

well guy said it was an overdrive tranny so if its not and no pto i wont use it was just a thought...i do have another tranny spotted but want some info on it from u guys to c if it would be ok to use...its a 5 spd in a log truck..newer model like an late 70s or early 80s...has a 366 bb in it my question is 5th gear is over and down instead of up...is this an overdrive and if not would the 5th gear help out on the top end any...thxs for talking me out of the auto didnt really want it just looking for a cheaper way than a nv 4500 to get the truck up to maybe hyw spd...gonna have the rear end of the school bus chked to c what the gear ratio isthanks 3B and Oldsub

My guess is the log truck has a Spicer 5 speed direct drive.
Is this of any help? http://www.chevyc60.com/the_transmission_page.htm

If not an OD transmission, then high gear will be direct, just like most all non overdrive transmissions.
If you have determined you need an OD transmission then that's what you need, there are no substitutions (other than taller tires and faster rear axle gears).
Also note that not all overdrives were created equal, ratios may vary from about .84 to a fast .61 or so. .8 is common in big truck transmissions, and .73 is common in medium to small transmissions. The .6x ratios are usually the second overdrive gears on some transmissions (double overdrive).

Grigg

thxs grigg...that site was helpfull...now i have something to go by as what to look for...havent made it back to the old log truck yet to see what it has for a trans or chk on the bus rear end but ill find out and let you know soon if im lucky OD but w/ my luck it will be a 1.1