Trans for my 223
You might be able to find an old Fordomatic for 223 Passenger car BUT it won't have bellhousing side mounts req'd for mounting in F Series chassis. It will require fabrication of an X member to support the transmission at the rear. Except engine now has 1 front mount & w/out 2 OEM Bellhousing side mounts stabilizing it, engine will topple over in engine bay as a result lacking stability.
Aside from mounting problems etc. A 223 I-6 with A/T behind it is dangerously underpowered, in my estiamation. My ex wife had a 54 or 55 Ford Car with a 223 I-6 & A/T, getting on an interstate was always a thrill, especially after it ran out of entrance lane. I can imagine what that would be like in F Series today w/ 70mph traffic bearing down from behind.
If I had your problem, I'd change engine & transmission as unit, using 300 (4.9L) I-6 or 302/351 (5.0L / 5.7L) SB which all have the same bolt paterns, plus offer 3 spd A/T, or 4spd O/D -A/T as viable options with safe operating capabilities, & most likely better MPG and performance also.
Either way you need at least 1 cross member, so what's a set of aftermarket frame brackets for engine mounts, making your truck capable of using plethora of late 20th century/ early 21st century power train combinations?
What I'm saying is if you're considering changing things around, change them in ways to upgrade everything about your truck, not push it farther back into last, past, century. Upgraded right, truck will appreciate in economy, operation, reliability, performance and so on, not to mention Worth. and Cash Value!
There are only two ways to "spend" Money that I understand.
I can either spend it as outright expense & it's gone for good. Or I can invest it wisely so it comes back worth more than it was when I invested it, or better yet saves/earns money until it does return worth more than when I invested it. NO. . . . .?
Of course I've been wrong before & I will be wrong again too.FBp


