Ignition is Pertronix I. Valve springs matched to the cam.Heads and everything else stock 2 bbl 1968.
Carb is 600 Edelbrock. Performance is just a guess.
I have no idea on early A fit.
to add to Darter6's remarks, the only difficult thing with these are the collector bolts. because they're higher up, next to the T-bars, it can be "fun" getting the bolts in and tight :)