I can't see getting to the goal with a SC, the Eatons just aren't made for that kind of boost. (They can do it but efficiency drops way down as well as life, normal operating boost limits are < 8 psi)
I can totally see a 300 HP engine if you:
1. Euro crank from deisel to ge the 2.1 stoker.
2. Top end pistons (IE JE, Weisco Etc.) AND Head parts Ti valves likely.
3. Turbo/Intercooler
4. Standalone ECU to replace the factory unit. (Motec, Electromotive, FAST)
5. Pay a top flight builder to assemble it! It doesn't matter how good you are, a race engine builder will build you a better motor because he has ALL the tools and cares about the result as well as having done it enough to not make mistakes.
6. The cam need not be that radical if your running a turbo, they actually like the grinds most EFI engines use.
Budget:
Long Block - My builder would likely be into it for about 5500 to 7500 $ US Balanced blueprinted 8.4:1 compression, full seal rings etc.
Turbo - the system I am installing on a Merkur XR4ti right now is:
Turbo - $750 To3/4 Hybrid from Turbonetics.
Wastegate - 300
Bypass/Blowoff valve - 300
Electromotive - $1700 You WILL NOT ever get the stock ECU to beat a standalone. Even BMW doesn't use their own computer on full race applications.
Plumbing - $800 (Oil cooler and water and Inter-cooler piping with me doing the fab work.)
Inter cooler - 1200 bucks, large custom unit made to sandwich with the radiator to avoid too much tub hacking.
If you want max power and longevity a dry sump system is in order, add another $2500 to $3000 US....
BTW the lowly little 2.3 in the Merkur turned 480HP at the rear wheels Before I did the dry sump the new inter cooler and the new turbo plumbing.
On a dyno run by experts not a hack tunning shop.
I fully expect to see 550 on the next run....
The financial math is left to the masochistic requirements of the reader.
Glad I'm spending someone else's money.....
Dave