i've set up a blow through system on a L20 running twin 40DCOE webbers on it and it works really well. All you need to do is run a rising rate fuel pressure regulator and run a blow-off valve before the carbi's also you'll need to run a good fuel pump ( I run a holley Blue ) The pump has to run 4-5 psi more than the boost your running.

HQ disks will bolt on to 240k or 200b sx struts but you will have to make up a bracket to suit the vl brakes

hq holden disks will bolt on to 240k or 200sx struts as they have the same bearing but you will have to make a bracket to suit the vl callipers.