Air FLow Research vs. Vortec on flow bench :)
 

I also took my Air Flow 220cc heads to the shop today, just for curiosity sake.......while we were at it, we flowed a new set of vortec heads, that they had at the shop, just to compare........WOW, is all I could say.........keep in mind the AFR's have 2.08-1.60 valves and the Vortecs were fitted with 2.02-1.60 valves......

.100 the AFR flowed 31.6 intake and Vortec was 68.5
.200 the AFR flowed 114.5 intake and Vortec was 143.4
.300 AFR 172.1 intake and Vortec 192.3
.400 AFR 211.6 intake and Vortec 223.5
.500 AFR 241.3 intake and Vortec 241.9
.600 AFR 265.6 intake and Vortec 246.3
.700 AFR 272.3 intake and Vortec ------fell off bad

.100 AFR exhaust was 78.5 and Vortec was 102.6
.200 AFR exhaust was 122.3 and Vortec was 140.8
.300 AFR exhaust was 154.4 and Vortec was 165.2
.400 AFR exhaust was 174.5 and Vortec was 184.8
.500 AFR exhaust was 195.7 and Vortec was 193.0
.600 AFR exhaust was 208.6 and Vortec was 195.7
.700 AFR exhaust was 213.0 and Vortec -------fell off bad


as you can tell..........Vortec is obviously a great street head, but I guess since we run .670 lift cams in the race cars, that the AFR is a better choice for what I'm doing with them..................just FYI :)

Had the vortecs been ported or otherwise modified other than the 2.02 valves?

220cc vs. 170cc? I would expect those results. Now compare the 180 and 190cc AFRs to the Vortecs and see the results.