My '85 Delta 88 had the 7A super smoger headed version of the 307. 1.25"x1.25" intake ports. It wouldn't rev over 4k.
Ours didn't have a tach so I don't know what rpms it was capable of. I do know, by January 1990 it was not running well. We got a bogus ticket on Super Bowl Sunday evening, coming home from a swap meet in Belton, Texas on Highway 36. DPS trooper in a Mustang claimed we were doing 75; no way with the load we were hauling in the car plus in a utility trailer.
Don't remember what all Dad had to do to it, but we did get it running better after that. Hauled that load and that trailer, loaded, to DFW that April for the Pate swap meet (then it was still at the Pate Museum of Transportation outside of Cresson). Sat outside on the shoulder for 3 days with a few thousand other people (vendors waiting to get in). The area had very bad rains for several days and the Corps of Engineers had to come on the property and okay it for occupancy. The place was muddy all weekend, the local farmers made bank selling hay bales for the vendors to put on the ground in their spaces. We got the wagon stuck twice on the way in, pulled it out with my Dad's '81 GMC Sierra 305(one of our parts store shop trucks), got the truck stuck getting another vendor moved out of the way, then they helped us get the truck unstuck.
The next year, 1991, I got to show Jimmie Vaughan and his then father in law around the meet on Saturday morning. Got to hear some good stories, and took them to the newer section of the meet that he didn't know about. That's where we found the guy that had a bunch of Buick nailhead speed equipment. The Offenhauser valve covers and intake manifold on his '63 Riviera came from that deal.....
He and I had met at the spring Belton swap meet, a few weeks earlier. Been great friends for 32 years now....