I have a 1990 F350 7.3 IDI. Truck originally had an automatic transmission. Previous owner had converted over to a 4speed trans out of (85-88?? Ford truck), but it doesn’t have overdrive. RPMs are just too high to be driving on the highway. I think it has 3.55 ratio, but still to high for like 70mph.

What model truck would have a good trans to swap over with a 5-speed with an overdrive? Should I be looking for a ZF S5-42? Thanks.

 

S5-42 or S5-47 will bolt up directly. The truck probably has a T-19b in it now. IIRC, the ZF5 is the same length as the T19 with bellhousing. You'll have to do your homework wrt. what clutch/flywheel to use. OBS hydraulics will work with some minor mods at the firewall, and the advantage is that you can get a complete pre-built pre-bled hydraulic set and not have to assemble and fill and bleed it (which is a PITA with our hydraulics). The other thing you gotta match up is the output(s) to driveshaft(s).

 

I did this on mine, you can check my build thread for some info and there's a ton of data on this in the FAQ thread.

 

The frame for m current build was an 85 with a 6.9 and T19, I dropped my 7.3 and ZF in place, and the driveshaft bolted right up. The cross member does need to be moved back a couple inches, though, but that's just drilling a couple holes. So, at least for a 2WD the five speed is a bolt in swap.

 

thanks for the info. I'll check out the FAQ. Now the hard part is going to be trying to find a good deal on one.

 

I have one in good shape. $400 local pickup on southeast Ks, Ok border