Whoa, whats up with this build?

440ci.
Victor Heads
Victor 440 intake manifold
260/269* @ .050 / .650" ish lift solid-roller camshaft
2.5" headers
Open Exhaust
1050 dominator

..13.2's @ 106?

Something is seriously wrong here, you could & should easily have a 120+ MPH build. Going from a 3.73 to 4.10 gear is worth maybe .2-.3 tenths at best and not worth the cost. What brand converter?

You have the foundation for a mid-11 second build in a HEAVY car without boost, you should be making near or over 600 HP on pump gas with a few changes [smaller primary tube headers & 250* / .600" solid-roller camshaft]. Sort out what's wrong with the power N/A before you stick the blower back on it.