an lt1 setup would work, but the optispark distributor is crap, and actually wouldnt be worth messing with....
heres a junkyard parts list for an LS based fuel injection setup
any ls1 based pcm will work, you'll just have to get it reflashed, many reflash for like $50.00
heres the list
12200411 PCM (LS1, Truck, S-10, Blazer, Express, others)
Wiring Harness for 12200411 (must follow Vortec L31 schematics for the 18436572 firing order)
Vortec 305/350 Distributor (has camshaft sensor in it)
Vortec 305/350 Harmonic Balancer (if your 383 is internally balanced, if not, retain your balancer and cut the thickness of the reluctor wheel from the hub)
Vortec 305/350 Timing Cover(crank position sensor provision)
Vortec Timing Reluctor Ring (goes behind timing cover)
Vortec Crank Position Sensor
Vortec Ignition Module
Knock Sensor (2001 Express Van w/ 5.7 engine)
injection intake and rails, professional products makes a decent setup...
injectors, ford 30lb redtops would be minimum, can be found on ebay very reasonable..
i have always made it a point to run a dbl pumper with a manual transmission..
if you have a bog off idle go to a larger discharge nozzle.. if you cant get the dbl pumper adjusted correctly you'll never get a vacuum secondary carb to work correct..