single pattern cams only provide marginal benefits in most cases if your running low restriction too flow, open headers,
the longer exhaust duration, on the exhaust lobe, timing,
aids and helps the exhaust, extending the time available, for exhaust gases, to exit the heads,
and scavenge the cylinders,
as it tends to aid power if your running a marginally restrictive exhaust system,
behind the headers ,exhaust collectors, as it provides a bit more time for the mass of exhaust gas to bleed down.
running an X-pipe also helps, mods that work well on a dyno or circle track car ,
with open headers don,t always provide similar benefits if your running a full length exhaust,
on the street with mufflers, third gen firebirds & camaros are known for having restrictive exhaust systems.
longer cam duration is beneficial at higher rpm power bands,to produce better power,
but higher rpms also result in less available time between individual exhaust pulses to exit the exhaust system.
(thus extended exhaust duration may help)
one of many of the reasons I selected this , crane cam below,
for my vettes 383, and of course I intended to use a wet nitrous TPI plate
with the modified stealth ram/tpi efi
http://www.jegs.com/i/NOS/741/05151/10002/-1
be damn sure you get a WET nitrous system, and retard the ignition advance curve,
the OEM TPI computer processor speed is way too slow,
and sensors won,t keep up and you,ll burn valves or pistons,
with a dry nitrous system on a TPI engine
http://garage.grumpysperformance.com/index.php?threads/is-backpressure-hurting-your-combo.495/
http://garage.grumpysperformance.com/index.php?threads/x-or-h-pipe.1503/
http://garage.grumpysperformance.co...-between-shorty-and-full-length-headers.1303/
http://garage.grumpysperformance.com/index.php?threads/exhaust-thinking-of-your-options.13115/
http://garage.grumpysperformance.com/index.php?threads/calculating-required-exhaust-pipe-size.11552/
http://garage.grumpysperformance.com/index.php?threads/my-current-corvettes-383-combo.430/