F150 rear end gear recommendation?

Assuming he had the budget. Would this be a viable application for an Underdrive unit that bolts to the back-end of a transmission.

He could have an axle like the 3.73 and leave the Underdrive unit in the high setting (1 to 1) when not towing and have the 3.73 axle ratio in all 4 or 5 gears, but when towing use the (1 to .8) Underdrive setting and have an overall axle ratio of 4.65 in all 4 or 5 gears.

I'm not very mechanical, but this sounds like it would be a viable application for an Underdrive unit. Considering they don't make 2 speed axles for standard pickups.

As far as money goes, a underdrive (if you can find one) will cost a lot more than a gear swap or tranny swap (you could likely swap gears and tranny for less than a under drive unit.) Underdrives are VERY pricey.

----------------- TheSnoMan.com

I know. I don't think anybody even brought up the issue of what will bolt up to that block. Need to figure that out. I'm pretty sure the Windsor won't work, but I forget where I heard that.

Not a problem, http://72.20.96.178/commerce/ccpc1174-1322-gm-nv4500-manual-transmission-adapter-kit-712552-712552.htm Whitelightning

The 351M/400 shares bellhousing bolt paterns with 429 and 460.(except for a few rare 1973 blocks) Tthe 351C does not as it uses a small block ford pattern. Also 351M/400 blocks cast in Michigan casting center prior to about march 1977 should be avoided as they were prone to crack water jacket in lifter galley area and none of these 351M/400 blocks are good overbore platforms.

----------------- TheSnoMan.com

To all:

Thanks for ALL your input! Now, once we tear down the body, fix what's needing it, we'll have a ton more info to make our decisions!

Thanks again, I'm always amazed at the amount of info one can get if they only ask on the NGs!

Thanks again

OldIr>>