elmariachi Jim, you are in cobra heaven in the Texas area. Not 100% sure about what you want to build, but the suspension for the street and the track are to different things. Street springs are in the 300-350 inch pounds where as the track setup are in the 450-600 range, this doesn't include shocks and tires. A Cobra is a whole different animal than anything you have driven before. Not to insult your machinist but if he have not built a bunch or FE motors, I wouldn't let him make mine the first.
They are not the same as a GM BBC or SBC. KCR, Gessford, Kuntz, Barry R. and Jay B. all have many years of FE motor building. About 275 years total, give to take 5. Build a stroker in the 484 - 527 range, sell the crossdrilled crank and rods to someone for a restored car or hang them on the wall for trophies.
Put a set of 307-308 gears in tha car, a richmond superstreet 5 spd with 2.87 first gear, and what ever motor you want. A hydro roller lifter motor, IMO is the way to go if setup right. Add an accusump to the car also if you go racing for both a preoiler and pressure controller on high G-turns.
Build a 600ft pound of torque motor. It will go just as fast and be more streetable. What kind of fuel system are we looking at?? Carb, Webers, Propane, FI?? Diesel is coming down the road.
Rick L. ps you have private e-mail.