The Stovebolt Site Forums The Shop Area Engine Shop 3 speed overdrivetrans with 250?

Howdy guys. My little 85 Chev short bed can with a 250 six 3 speed orginaly. It now has a 305/th400/Doug-nash overdrive. I want to convert it back to inline 250 3speed od. ( and sell the current running gear.) I have a chance to by a 3speed od for $75.00. How good are these transmissions? The rear end is stock that came in the truck.( i was told by previous owner) I really don`t know what stock would be. But turning the wheel and counting it looks like 308`s. Would a stock rear end be that high?
Mostly i would like to know about the 3 speed. Thanks fella`s.
Slider

Slider,
Does the OD have a 4 bolt or 7 bolt side cover? If it is the early 4 bolt type you may have trouble finding a front yoke to match up with your u-joint/driveshaft as the later trucks use a larger u-joint and fine spline yoke. Also it is non syncro in first gear so you probably would not be happy with it in a later truck. I rebuild and install these OD's in older trucks and they hold up fine. I have one in my 56 behind a 350. If you can get the later Saginaw (7 bolt) it would probably be better for your application. It is possible your truck came with a 6 cyl and 308 gears, but probably more likely 350's. Fred

I don't know if they would put that ratio behind a 250, but I have an '85 K10 shortwide with 2.73 axle ratios. The engine is a tired 305. It's really too tall a ratio for the 305. Cruises nice on the highway, but it's terrible slow getting off the line. I plan to put a 292 in next summer. That 4 1/8" stroke should love those gears.

If your axle ratio is indeed 3.08, I think the overdrive would be too tall for use with a 250.

I want to thank you both for the reply. Just what i need to know. Have a fun day today.