Not sure of the cam specs that Tlowe had during the turbo 250 dyno?
But I would think it was not for a turbo application, might have had too much duration & a tight lobe center. Those two combos are most likely not ideal because it would make the engine not to RPM that high & make good power for a turbo application.
The turbo you currently have will not support 600 HP, might be able to squeeze 375-420 HP range.
IIRC, you said your turbo can support 550 HP,, only w/a small displacement 4 cylinder type engine, not your 250 CI engine.
The guys in Brazil are running 100% straight methanol for fuel & run 30-45 psi of boost pressure. That is why they can make so much power. Also, IIRC, those guys also can make 1000 HP on stock cranks stock main caps.
