Edelbrock Performer RPM intake. (will lose nothing in low end power to the 50 year old design of the standard Peformer)
Edelbrock E-Street heads
Small cam around 206 to 212 @ 0.050" on the intake, a little more on the exhaust. 110-112 lobe separation.
Not a Galaxie person aside from dad using to own one a long time ago, but the above is a good recipe for grunty torque that will move the heavy car along nicely. No aftermarket torque converter needed. The heads are a key part, as the factory heads are utterly junk. You will need hardened pushrods, as they use guide plates. Also aftermarket rocker arms. Don't forget to check for rocker geometry any time something is changed in the valvetrain.
The heads are surprisingly affordable, and work fine with a small, flat tappet cam. Key component of the combination. Heads have 1/2" head bolt holes to allow them to be used on 351W heads. Must use head bolts with bushings to neck the 1/2" down to 7/16". ARP part is listed below.