Perhaps a more objective analysis could be attained by considering dyno results; in particular "power under the curve".
That said, it is worth mentioning an analysis of results would show the
(FBI) ZR-1s produced the fastest 3-car team aggregate
5* out of 6 attempts at the local Crown Point Corvette Club's annual Corvette Shootouts*. The event is made up of Chicago area Corvette clubs, and has been flooded with LSx's, and last fall a couple new LTx's. Various videos showed time and time again the lighter LSx cars jumping out front off the line, but at the 1/8 point the ZR-1s had reeled them in and beating them at the "top end".
*The Team Trophy was not awarded to the ZR-1 team on two occasions; one year the ZR-1s were not registered for trophy runs (but time slips showed they would have won had they been registered), and (for one year only) the trophy was tied into bracket racing rules instead of the aggregate speed of the top 3 club cars.
Analysis of the last two WANNA GO FAST events in Chicago clearly shows two things: 1) Forced induction dominated the 264 cars participating in the (2014) event, and the top 45 out of 264 speeds were all forced induction (with one possible exception), and a good number of them used the DOHC architecture. (See list below)
WANNAGOFAST Monee, IL 6-21,22, 2014:
Nissan GT-R Alpha 16 (Twin Turbo)
2006 Dodge Viper (Nth Moto) (Twin Turbo)
Nissan GT-R Alpha 16 (Twin Turbo)
Nissan GT-R Alpha Omega (Twin Turbo)
2011 Lamborghini Gallardo Superleggera (Twin Turbo)
Nissan GT-R (Twin Turbo)
Nissan GT-R (Twin Turbo)
Mercedes-Benz E63 AMG (Twin Turbo)
2012 Nissan GT-R (Twin Turbo)
1994 Toyota Supra (Turbo)
Nissan GT-R Alpha (Twin Turbo)
2008 Porsche 997 Turbo (Twin Turbo)
2006 Dodge Viper (Twin Turbo)
2009 Nissan GT-R (Twin Turbo)
Toyota Supra (Turbo)
Toyota Supra (Turbo)
2000 Pontiac Trans-Am (Turbo)
Mitsubishi Evo 2 (Turbo)
2010 Nissan GT-R (Twin Turbo)
1997 Toyota Supra (Sound Performance) (Turbo)
2013 Nissan GT-R Black Edition (Alpha) (Twin Turbo)
1985 Oldsmobile Cutlass (Turbo)
2011 Cadillac CTS-V (Vengeance) (S/C)
2006 Lamborghini Gallardo (Heffner/Nth Moto) (Twin Turbo)
2006 Chevrolet Cobalt SS (Turbo)
C5 Corvette (N/A)
2012 Nissan GT-R (Twin Turbo)
2012 Chevrolet Corvette ZR-1 (S/C)
2004 Lamborghini Gallardo Heffner (Twin Turbo)
2010 Corvette ZR-1 (S/C)
2009 Chevrolet Corvette (S/C)
Mercedes-Benz SLS AMG Black Series (F/I)
2009 Chevrolet Corvette ZR-1 (S/C)
2006 Dodge Viper (Twin Turbo)
1993 Mitsubishi 3000GT VR-4 (Turbo)
Nissan GT-R (Twin Turbo)
1998 Chevrolet Corvette (Tigershark) (Turbo)
Dodge Viper (S/C)
2006 Dodge Viper (Twin Turbo)
Nissan GT-R (Twin Turbo)
Nissan 300ZX (Turbo RB26)
2000 Honda S2000 (Turbo)
2003 Chevrolet Corvette (S/C)
2008 Porsche 911 Turbo (Twin Turbo)
1993 Toyota Supra (Turbo)
There's little doubt the 4-valve DOHC architecture has significant advantages over OHV (pushrods), at least in some venues.
Car and Driver article: DOHC vs. OHC:
http://www.caranddriver.com/columns/...mg-slug-it-out
But that said, where the DOHC architecture has a performance advantage, equally evident is the $/hp advantage of the OHV approach.
Mitigating factors?
Kevin makes a good point regarding technological advances. But, his insinuating that (peak?) hp/$ is the quintessential approach to analysis dismisses other virtues that other architectures (DOHC) have, e.g., power under the curve (for one!).
How about durability or driveability?
And, so it goes...