Good mods to make torque in a 440

The gear ratio I will be running is probably 3.23 because I have a couple of those around. Right now it has the stock 14 inch tires and hub caps but I will be changing to some better looking wheels and tires probably around 275/60/15's in the back. I bought this car on a whim on my way to Chryslers at Carlile this year. 1966 belvedere 4 door, white with brown interior, Texas car so it's really clean with no rust. Interior has already been done and it has a running 400 with an Edelbrock carb and dual exhaust. The 400 has a dead miss at idle and I suspect someone installed it with the wrong converter or balance weight. I figured if I am going to unbolt the trans to change the converter I might as well drop in a 440. My buddy had built this short lock some years ago for his Coronet and never used it. I don't even think when he dropped it at the machine shop that these were the low compression (motor home) Pistons. Long story short he was tight for cash and I seized the opportunity to get it. I only paid $1400 for the car and I gave $600 for the fresh short block. If I spend another few hundred on the motor stuff and wait till my other buddy who paints to get tight for cash I can get the whole car done for about 4 grand. When I first saw the car it reminded me of the 66 Belvedere 4 door I used to street race with a 426 hemi. automatic and 4.10 gears