now I,d point out that you can make the car run fairly well with a different cam, better heads and a new intake.
carbs operate best at a fuel pressure level of about 5 psi, your cross fire throttle body injection fuel pump operates at about 12psi-15 psi thus a fuel pressure regulator swap will be required and a different fuel pump is not a bad idea.
viewtopic.php?f=55&t=211
THE OFFY base IS STILL CURRENTLY MADE, and can be adapted, to use twin throttle body injection or two 500 cfm carbs rather easily, swaping to a much better cam will allow you to make a good deal more power but swapping to a higher stall speed torque converter and a 3.54:1-3.73:1 rear gear is going to make the choice of effective and useful cams far better.
your cam choice will depend on the cars gearing ,compression, displacement and drive train, so do the required research or at least ask questions before selecting a cam to match your application.
If you want to keep the rather impressive and slightly exotic cross fire look the offanhauser dual quad intakes a great option.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=OFY-5893&N=700+115&autoview=sku
http://store.summitracing.com/partdetail.asp?part=OFY-5902
http://store.summitracing.com/partdetail.asp?part=OFY-5903
the basic crossfire manifold is a HUGE restriction EVEN if ported to the max, the XRAM is nothing but a single plane carb intake with a mickey-mouse adapter to allow the TBI injection to be bolted on.
read thru this
http://www.swko.net/~lionsden/crossfire.htm
either the OFFY or the SY1 intake base, with a custom top plate will be a HUGE improvement, easily able to support 500hp or more on a correctly configured engine with decent heads like the AFR 210cc or AFR 195cc
http://www.airflowresearch.com/210sbc_rh.php
and a decent cam like this crower
http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=00404&x=25&y=17
installed in a 10.5-11.0:1 cpr 383
but keep in mind youll need a 3000rpm stall converter and 3.73:1 rear gear to run those
keep in mind INTAKE HEADS AND CAM and COMPRESSION ALL must be upgraded to get full flow into the heads , so that the power levels your looking for can be achieved,and the stall and rear gear must be changed to use the significantly higher rpm power band effectively, but theres no comparing the results after the mods are correctly made, youll have well over 140 plus MORE hp,(plus) if you do things correctly