New to V8's. 340 or 383?

Hi ho
I have and doing a restore 70 Duster, I had bought 2 440 cheap had one clean up and some machining,
With that said after tring to get the 360 out of the car, and its a small block, its tight, and after researching the torq and power are real nice, the 340 would be great for an expensive and extensive build. The 360 is relatively cheap to get and rebuild. But a tight fit but I know it fits cause I got it out. 383 , 400, 440 blocks are heavy. And are going to add bucks and fitment problems.
Your call.