A little background: 1966 F100 Flareside (I'm usually in that forum), originally with 352 w/3 speed manual, 3.03 (column, moved to floor). Currently have it mated up to a FE 390 from a 1972 F100. Has a little cam with 4 bbl.
I had an opportunity on a 4 speed toploader from a 67 Cougar (thats what the guy said it came out of) that he wanted to sell cheap. Never happened, I think he had to blow town fast????
Anyway, I do want to get rid of the 3 speed and thinking of finding another 4 speed toploader or something along those lines. Looking for suggestions, I don't like granny gears, but, I can live with it. I do like to burn thru the gears and the 3 speed don't do it.
Also ease of installation as I'm just a backyard mechanic and novice trans guy. Thanks for any feedback/recommendations.

 

Cougar or Mustang model might put the shifter too far back.

Measure your 3 speed overall length.

Compare to chart in the following link.

You need to check input length as well, as there are two depths. You may have to do driveshaft work as well, and maybe a crossmember move.

You will probably want the 2.78 first gear as well.

4th is 1:1 just like your three speed, so you'll be shifting at a better interval but still have the same top speed and cruise rpms.

Tailhousing ID Chart

 

Thanks 85. I forgot to mention I have bucket seats. Good point on the setback. I'll do some more measure and research.