I have a 83 f150 2wd I just put in a new 300 and in trying to get a little better mpg I want to put in a 5speed in place of the old 4speed... ok other then the trany what else do I need to get to do this? is the cluch and bell. the same or do I need a setup off a od 300/6... driveline? what kind of mpg should I get with this setup I have a 8.8 with 3.50s right now

 

50% is the way you drive it, the other 50% is gearing and tune of the engine. So, drive easy, slow, and low RPM. Have good plugs, wires, fuel filter, etc.. A 5-speed with OD paired with 3.55's would be fine for highway cruising. I have 3.50's in my 9" and a 4-speed with a 4th gear of 1:1. That is not good for 55mph, lol.

 

Don't forget that the ZF 5-speeds come in a number of flavors. If you want a heavy duty tranny, this is the one. You want the one that fits the small block engines, not the big block or the diesel.

Ford also made a light duty 5-spd. tranny called the M5OD. I dunno... maybe that was a Mazda creation. It would do the job for you too and is probably cheaper and more readily available.

 

Both those tranny's use a hydraulic clutch and will require a bit of fabricating a mount on the firewall for the main cylinder. The "Mad dog" will be some cheaper but the ZF probably more reliable.

There is absolutely no way to project what the mpg will be...pick a number between 10 and 22. There are some big mpg threads on this Forum. When you find them and read them you will see what I mean.

 

Probably be easier to use a T5 with existing bellhousing - IIRC, the only mod is either using an adapter plate or drilling the holes in the bellhousing to line up with the trans. case. Aside from that, yes, you will have to do some slight modification, possibly. I could have sworn the 80s F-series no longer had the Z-bar clutch and were switched to hydraulic as early as '83. I replaced an '85 F-150 and F-250 clutch and they were both hydraulic. If yours is the old Z-bar clutch, you will have to remove the linkage and parts and convert it. Not sure if the pedals are the same, but if not or you can't modify yours, you will need one from a truck equipped with a hydraulic clutch and use the same master cylinder and a compatible slave cylinder, throwout bearing (unless the slave and bearing are single unit), and clutch parts - may be able to get away with just the friction disc, depending on what size your original clutch setup is: 10" or 11". You will probably also want to get the driveshaft from your donor as well - you will need to take measurements and make sure everything will fit. Worst case is you have to shorten your existing driveshaft. Can't think of anything else off the top of my head. That's about the only input I got on this.