http://www.mortec.com/castnum.htm
Block:
3932386....302.....69....4...Z-28 Camaro
3932386....327.....69....2
3932386....350.....69....2 or 4
Heads:
3932454....69-73...307
3932454....69-79...350..........Truck
If the block and heads have always been together, it's a '69 truck 350. If not, at least the heads are truck 350, most likely from the 70's.
Figure on the heads being performance junk. The blocks were known to have casting & machining problems (lifter bores not properly lined up to the cam, starter bolts not properly placed, core shift). If it ran okay and doesn't have any weird wear evident, it's probably okay for rebuilding (if the bores aren't already 0.060"-over).