The people working at a normal parts store don't really know much when it comes to our cars.If you have a local speed shop I would go there.They can usually help you out and if you become a regular you can sometimes get good deals.And make some cool friends that share the same passion.
Use caution either way and remember your build parameters. If you're building a street engine that will rarely see the north side of 5500 rpm you do not need a steel crank, a cast crank will work fine. 2 bolt main blocks work fine for ALL cleveland builds (all we use in the racecars are 2 bolt). Beware the cheap knock off parts from china. If you do not get the "warm fuzzys" from whoever you are working with walk away. If you have any questions let me know I can find out if parts are worthwile or not. The friend I crew for is a buyer for performance parts at an engine parts distributor. He also builds all our race clevelands.
Low buck, touring style, '73 Convertible "rolling restoration", 351c, 2v heads with a shave and a haircut, Performer intake, Holley 650(ish), roller rockers, screw in studs, guideplates, stainless valves, Duraspark / Motorsports MSD, T-5 conversion. 1-1/8" front, 3/4" rear swaybars KYB shocks and some home brewed subframe connectors. Future plans; JGC steering box, Cobra brakes and... paint, interior, etc.
When I die I want to die like grandpa, peacefully in my sleep... not screaming, like his passenger.