Id agree most people underestimate the A Series. To make around that power target your going to need big revs and a cam that makes power up high in rpm, eg big duration/lift. Its common knowledge that with an NA engine the bigger the cam the more compression you can get away with running as the larger cam effectivelly lowers dynamic compression from overlap. Same thing applies to boosted engines, bigger cam more comp you can run. To me 8:1 seems a little low, maybe between 8.5-9:1 would work better with suggested bigger cam. What fuel you running, 98? What turbo manifold, try and stay away from a log style for bigger cams?
Were building a boosted a12 atm using parts laying around and on LPG. Just running a t25g from sr20, 270x300x76 fmic, prob just cast acls. Should do around 120kw atw on 20pound+. Will be running about 9:1 with cam around
230@50 on 114lsa.
I think the best money you will spend will be on the head, flow test before and after, chase every little bit you can, then run 25+psi with a good cooler. You will get good power from it prob suprise a few non believers!
Also for the record to give an idea, a while back i had an et pulsar, 100%std motor, t28, front mount, 3" syst, microtec etc did 140kw atw on 19psi.