seeking info

[Dav]

have an 88 2wd ranger. axle is '84' 345 ratio. on the highway it cruises at 65 comfortably but is straining a little at 70. it doesn't like doing 75, which is usually the right lane speed here in tampa
my questions; will any 7.5 diff fit in my axle housing, irregardless of the source( ranger , aerostar, explorer, et al) ? if i find a limited slip diff, will it fit? if i go to a 373 ratio, am i going to get a bit more highway speed (i think it would be at the cost of slower acceleration)
i have the 2.9 with automatic. both are scheduled for rebuild later this year. the plan is maybe a mild cam for more hp but nothing outrageous

 

[adsm08]

Yes, and 7.5 carrier will go into your housing.

But, going to 3.73 gears won't help your highway speed issues. It will make it worse. A numerically higher gear ratio is a lower ratio, so more accel, less top speed. The sad reality of things for you is that your truck was never really meant to go much past 55. That was the national speed limit in the 80s, and that was about as fast as the people designing it ever thought it would need to go. That's why there is a little red box around 55 on your speedo. If you want to do a gear change you need to look for something like 3.27, or 3.08 which I don't think they made for a 7.5.

 

[rusty ol ranger]

The biggest thing working against a 1st gen is aerodynamics. How fast could you push a piece of plywood into a 70mph headwind?

Either way, id hold off till you rebuild it. Im going to guess its on the tired side, any 2.9 i ever had had no problem runnin 75-80.

 

[Dav]

okay, info is what i asked for, any 7.5 will fit my housing but i need a 308 (code 82 to go faster- the only ratio listed that is lower than my 343 . if i can find a D2 in a B2, i will jump on it just 'cause i want the posi in case i go north in the winter
as to rebuilds, the ammco shop screwed my on my 95 ranger trans so i won't go there. and it was sub'd to global power train so i will never buy a motor or trans from them i priced rebuilding the 95 (2.3) a few years ago and it came out around $1200. i've rebuilt plenty of motors over the years and it has lost it's fun aspect. fortunatly, with an 89 parts truck i can redo that motor at leisure and still drive the 88