According to gear ratio and rpm (but without knowing how tight or loose the converter is!), it should be trapping somewhere around 7,000 rpm. If it were a clutch car (locked up) it would be around 6700 rpm accounting for an inch or so of tire growth at speed. Do you know what the car was being shifted at before? I’m going to go out on a limb and say the PO was favoring the slightly smaller cam because the converter may have been tighter than anticipated with the other cam retarded four degrees. It's really kind of a "WAG" how it's going to react without knowing the engine's intended power peak based on head performance. Any idea who did the CNC work on the W5's and what valve size they are? Probably safe to stay on the conservative side and guess 300 to 310 cfm based on other W5 heads that aren't full of filler rod or epoxy.