Nick,
The Pinto engine & box are extremely robust engines. The bottom end is able to withstand a fair amount of tuning (Circa 140-150hp) before needing any real form of upgrading (Ditto the G/box) provided they are in a serviceable condition.
You are indeed correct that the inlet ports are of a different shape but I have never encountered any problems with this when running on carbs.
Anyway enough of my ramblings and on to the important bit.........
Over the course of this winter I have been upgrading to a big valve head and should be completed in the next couple of weeks. Provided there are no disasters in the pipeline (Bent valves etc...) I will have a spare injection head that, if you are a member of RhoCar, can go for free.
The head is in excellent condition, the ports have been reprofiled to a good standard (Not done my me!!) and is fitted with a Piper road cam (Showing wear on lobes, but by no means the worst I have seen). When last on a rolling road this head on a standard bottom end gave a genuine 104hp @ wheels (A standard engine usually records circa 86/87hp) with the R/hood 4 into 1, and DHLA 40's (although fitted with extremely small chokes for midrange rather than outright power).
Let me know if you are interested......