Hi All
I have a 1968 ford C4 tranny that works and shifts fine at normal driving and even hard exceleration conditions. My problem is when in city traffic shifting from first to second or second to third. from lower gear it will freewheel and won't upshift until rpm's rise then it will shift. can anyone help? thanks for any suggestions

 

What if anything have you done/checked so far?

 

Well, finally one that's just about up my alley. I used to love rebuilding these as they were simple and easy (compared to the stuff we have today).
Always start with a fluid check; both level and condition. If all is Ok, then you could do a line pressure test, but that really doesn't matter as the unit would probably have to come out for repair.
This was a really common problem on this trans and the C-6 (the bigger sister), and as for the delayed shifting, I would wonder if this 1) is built for this, as it's in a 'Stang. 2) On something this old, it's probably got a worn governor that's loosing pressure. They make a sleeve kit for these that will fix the governor and you can always get a shift kit to make it shift just about any way you wish.
These trannys were very durable, giving, and very well known. You shouldn't have any problem finding someone to build it for you.