Well... The P&A is no good on this one since mine only shows the 69 Camaro for the "Pump Assembly" (No 67 or 68 Camaro listed). However, all is not lost becuase it DOES
show the "Valve Assembly (Straight Hose Pipe)" as P/N 4914356. This was used on the 60-62 Corvair, 67 Camaro and 69 Chevelle.
You should be able to get a Corvair unit fairly cheap since the Corvair guys are known tightwads (myself included, since I now own a 69 MONZA CONVERTIBLE
If you need some contact info for used Corvair parts houses, let me know...