Going to rethink trans when putting the 292 in my 55


http://forums.y-blocksforever.com/Topic66227.aspx 		Print Topic | Close Window

By junkyardjeff - 13 Years Ago
My 55 presently has a 351 with a wrong cam so I bumped the gears from 2.79 to 3.00 and the motor is spinning more then I thought at 70 on the highway,those gears perked it up some around town but not as much as a I would like so I am thinking about going with 3.25 gears and a AOD with a Lentech valve body. I wanted to got with a FMX so I could use the original type starter but the AOD is starting to sound good so I can have a gear so it will run good around town and go comfortably down the highway.
By MoonShadow - 13 Years Ago
I'm using a AOD behind my Y-Block with a 3.9 gear ratio. The engine turns about 2200 in overdrive at 60-65mph. I'm not sure if the 3.25 will be enough. I plan to put a set of 4:10's in it in the spring. Chuck
By junkyardjeff - 13 Years Ago
If 3.25s wont cut it will 3.55s work.
By MoonShadow - 13 Years Ago
I don't know for sure if the 3:25's wouldn't work. Just my experience with the AOD. Chuck
By charliemccraney - 13 Years Ago
Do you actually know how fast the engine is turning at 70?
By MoonShadow - 13 Years Ago
About 2500 for my setup with the 3:80's. Chuck
By The Master Cylinder - 13 Years Ago
In case anyone is interested the formula is;Smooooth rpm = mph x gear ratio x 336 / tire diameter Smooooth
By charliemccraney - 13 Years Ago
MoonShadow (11/29/2011)
About 2500 for my setup with the 3:80's. Chuck


Oh, that was at Jeff.

For that formula, if you have overdrive, also multiply the overdrive ratio to find the overdrive rpm.