Interestingly enough I have some of our flow data from 1978, we ran Enderley Bird catcher and 871 blower 30-45% overdrive, a 990 pump tested on 7/24/1978 was 15.1 GPM at 4000 rpm, now the 4000 rpm is cam speed not crank speed, and those motors back then were not spinning 8,000 rpm, now our 1100-1 pump @ 10% over drive it flowed 17.82 GPM and with 14% O.D. we were at 18.53 GPM and used a 1071 at 50% over.
Todays pumps are into the 100's in Gallons per minute and the blowers are 1471's, NF/C's run 21 gallon pumps with 671's but have seen 9,000to 9,5000 rpms add the overdrive and you are easly seeing why these cars make so much more Horse Power than we did in the good old days.