how is he running 4psi with that blower? that doesn’t make a whole lot of sense to me. with the stock pulley, that m62 puts out ~10psi.
i have that same blower on my 2.2L ecotec cavalier and i see 9-10psi with the stock pulley. the 2.2 that comes in cobalts and G5’s is basically same eco thats in the 03-05 cavs and can take a good beating before something breaks. it all comes down to how well its tuned, though.
i agree with everyone else though, heavily modding a DD is not the best idea.
Reliability becomes an issue