bhp

[Watson, Bill]

Pre '72 was SAE Gross
72 and later is SAE Net.  Most of the power 'loss' was the way in which
it 
was measured.

gains in last 25 years are technology.

Overall; Gross; 59?F, dry air, sea level.  Power at flywheel.  Open
manifolds/
headers, no air filter assy req'd, no accessories.

Net; 77?F, 32% humidity, sea level (This is already a 3% loss)  Power
also at 
flywheel.  Full factory exhaust system as installed in car.  Full intake
system with air filter, et al.  All accessories (including things like 
mechanical fans that were conveniently forgotten in the 60's) installed
but 
not taking more than 'straight line' power.  A/C, P/S, Smog pump,
Alt..... 

Typical drop in measuring of 'identical' engines in 71-72 was not 100
HP, but 
around 25% from what I've studied.

More in g-curve user's manual.

Bill