dual carbs & tunnel ram OR M1 and 850 dp????

Jim, i bought the "squik change spring" kit, it comes with the plastic covers with access plates to change springs, they have vacuum ports that you connect a hose to each one, this balances them out somewhat so they open together, i would start off with the med.-light springs. On the PVs, i ran 5.5s if i remember, you need to check manifold vacuum "in gear", i think mine were 3 inches below my reading.