Since there is a exception (Article 1 para 4(b)) to the 'saving clause' for Article 21 in the India US tax treaty, can't I still claim a standard deduction while filing as a resident alien using 1040 ?

Every one who files resident tax return gets standard deduction (unless you choose itemized deductions). It has nothing to do with tax treaty or "saving clause."

But, can I still avail the tax ttreaty benefits?