Cams
The purple shafts may be old, but they will work well if the head porting is set up closer for a single pattern cam or useage of one. A dual pattern cam is helping the exhaust. If the head had a better than 75% exhaust to intake ratio, a single pattern cam may very well do better. As the percentage of intake to exhaust flow narrows, a single pattern cam does better because to much exhaust is like to much of most anything else....not good.
Allllways change springs to match cam..it's cheap potatos.
The Purple cam is rated @ 248 @ .050. Look for a cam within 4*'s of that for approx. the same or similar performance. However, I would look into more lift. As much as the head can support. Have the heads flowed to know where it stalls and get a cam that lifts to just at that point or slightly less.
This will provided max. performance from the head and cam.
How old is the Stealth? Or what exact version is it? It really is not a bad intake at all. A 750 cfm is about right for the most part for the cube size. (360) More cfm shouldn't hurt it though. Considering it is a track car.