I really wouldn't worry about the issue of lack of low down go, as your car will be so light.
Leave the port size alone, opening up larger will slow air speed, which is not what you want, keep the inj head, Roland(the mad professor) at HT racing is a god of Pinto, he's done some for me over the years.
The usual route with 2l pinto is use +90 v6 cologne pistons and over bore to 2086cc, you can keep all the std internals just use arp rod bolts and flywhel bolts, lighten the flywheel, you don't need to keep a heavy one in your car, this alone will make a surprising difference in terms of cost/result, use a piper or kent, newman fast road cam, anything hairier will lose bottom end, but really not an issue in your car.
I assume you are keeping the std ecu ?
What is your power goal ?
tabetha