Budget is key here. 440 source sells 2 stroker kits, 438 and 496. If I were looking for 425hp out of a 383 I would go with the 438 kit (will still rev similar to the 383) $2200, then a set of trick flow 240 heads $2000, and I think I would try the trick flow track max roller cam with some howards roller lifters $750.

I would shoot for sub 10 to 1 compression, figure the above parts will cost around $5000, another $1200 in machine work and assembly costs, then timing chain, oil pump, gasket set, dizzy drive, fuel pump rod, push rods, rockers, cam bearings, freeze plugs, etc will cost $500ish can easily cost you around $7K thats if you have an ignition system, carb, intake, fuel pump, water pump, balancer, wires,tin covers, etc....


If that is not in the budget, I think with a set of 906 heads ($600 from indy all built and ready to install), a set of pistons close enough to stock weight that you dont have to get the rotating assembly balance 10.8+ to 1 compression, and a stout flat tappet cam, will get you plenty of power, cost would probably be around half of the cost of the above engine...


good luck, I always liked 383's, revv-y and torque-y...