i'm active over at CFIV too
crossfire manifold will not bolt up to most '87-later head
,so you will have to put earlier heads on the 305 block
port matching the manifolds to the heads was not done
by the factory,but does help.sycronizing theT/Bs will
only be needed if they are out of sync,to syncronize
them,you need two special tools to block the IAC valves
and a pair of sensitive vacume gauges,can also make
some simple "water columb"gauges out of vinyl tube.
A 7747 ECM from '87-early'90s chevy pickups is often
used as an upgrade ECM for crossfires(i beleve a
custom chip is needed)it's a faster more modernECM
that uses an erasable chip that can be re-programmed
while the original c/f chip cannot,chip must be replaced
with one that has different program.Not sure what ECM
a '91 TBI camaro uses,but it's pretty close to a 7747
and has the same plugs,original C/F ECMs will not plug
in.
Modifying my manifold involved using a tig welder to
build up the intakes to each port about 1/2"higher
than original so the intakes could be enlarged and
given a"bellmouth"or flared shape with a rounded edge
to grab more air with low resriction,the rest of each
runner was then hogged out about 1/8"all around and
the siamese ports were also smoothed.To better clear
the modifications,a 1/4"thick lidspacer was made of
aluminum to raise the lid 1/4"above the manifold.
decided the heads could benefit from some work too,
so removed and ported-intake ports matched and
smoothed just a little,lots of bowl work for both
intake and exhaust,streamlined guide bosses,reworked
and slightly raised exhaust ports,a little unshrouding
work around the exhaust valve
Rest of the engine is
stock '84 vette L-83,including cam.Once back together
the difference was unreal
instead of going lame
above 4200 rpm,pulled strong to 5200,easily revs to
5500 and beyond-i'd say this added at least 40hp/
30-40 FTLBs torque. Did the hop up in '95 and still
very satisfied with the performance! with big stereo,
stout SFCs,fluid coolers,air system,extra crossmembers
4whl disc,etc etc my car is heavy,about 3800 i recon
(if this engine was in my 3200#'69 it would really
rock
)
