318 build problems & new direction

OK, so my shortblock build uncertainty path is now certain. I bought a standard bore 340 block cast in 1969. Included is a steel crank and rods. No pistons. Also included is the windage tray. I will bore to 4.07", and not look back. I do have a question. The main caps had normal hex bolts. Caps 2/6 did not have extenders for tray. A quick look at Hughes, and I can get an ARP entire set for over $100. Why so freaking much? Any other options? Is finding just the 2 cap bolts with extenders difficult, and if i do, is it crazy to mix them with old?