69 Dart 340 Swinger Street/Road Race build

My son broke his wrist a few weeks ago racing and I was out of town for work, so unfortunately I was not able to work on the car much lately. But, I'm back on it so I should be making good progress moving forward.
I am aiming to be driving it this summer. Probably not til July/August i'm assuming. I'll make quick work of the front suspension and then move on to the interior next. My big hold up is going to be the direction I go with the engine. My ultimate goal is a nasty 340 screamer, but that's a pretty expensive route at this time when I'm dropping a lot of $$ on the rest of the car. I am also leaning towards a semi-budget 5.9L Magnum build with forged pistons, rods, aluminum heads, and the BW S400 75/96 turbo I have. I could assemble this engine myself. The thought is to go the less expensive Magnum route and then in a few years build the 340. I'm supposed to get a call back from Opel Engineering today to go over engine options so i'll see what he has to say.
I'm not really a car show guy, but I will try and make as many Downers Grove cruise nights as possible. That show is incredible with the level of cars that show up.