You have whats commonly called the suck through intake design (early TI '84-'87). Meaning the turbo sucks air through the throttle body. As opposed to the blow through late TI and TII style. Where the turbo blows through the throttle body. To intercool the suck through design requires comstom modification of the intake. And even then is inferior because it flows less and stacks boost at 16 psi. Best to convert to the blow through design if you want to intercool.
There are only two turbo dodge heads used on these cars (not including DOHC). The G head 84-85 and the 782 86-up. The G head flows a little better, 6-7% i believe, therefore makes a little more power. The 782 however makes more torq. I say stick with the stock head and get a 88-up roller tbi cam and roller follwers. More agressive cam and much smoother than the slider cam.
14 psi is not a problem on a non-intercooled set up. Never had probs with my old suck through design. If you wanna be cheap, ditch the custom cal idea, and go for the manual boost controller instead(about $20). If you want boost past 14 psi, look into a water/alcohol injection setup. One can be made VERY cheap. Or the always better solution, convert to the newer style intake and intercool.
Your car also should have the A520. Basicly a A555 without the hardend gears. Get a chrome moly end plate and it will be plenty stout.
Enjoy your new found power,
Bob