I have a new 1406 carb. to install on my '70 Torino Gt with a 351C 2V. motor and a C-4 auto trans. The motor is slightly above stock but nothing big. It has a slightly bigger cam and a 4-bbl manifold on 2bbl heads. I am wondering if anyone has one of these carbs. on a similar motor and what if any changes did you make to the jets,rods,springs ect. to get max. performance. Thanks, Chris

Just bolt the carb on and give it a try.
Unless someone has the exact combo, you might not find anyone who has the exact tuning answers you need.
I am running an 800 Edelbrock right now and have only had to change the step up springs to get satisfactory performance. Of course tuning it with a wide band O2 meter on a chassis dyno would work best.

Yea thats about what I figured but I thought maybe someone had an idea. I am sure it will run fine out of the box as these Edels. do (unlike a POS Holley) but was maybe thinking of going up a 2-3 jet sizes for a little extra. Thanks!