summit doesn't have a 19x27 with pass. side inlet and outlet. Get the 380325 or 380328 (both crossflow)and use a early(66-76 289 or 302) Bronco top hose, it fits perfect.
I don't know, I had already moved mine when I swapped radiators. I would thnk the 25" would be ok. Measure to see how much room you currently have between the battery and the radiator, if you have 4" or so clearance, you should be ok, with the 19x25 at least.