engine opinion plezzzz

[Corbusa]

Hey guys , its been a long time since I really turned wrenches on any engines , its funny how I used to live for it, building automatic trans and working on heavy equipment kinda burnt me out . But then I got the ZR and its kind of stated the flame again. But my question is ( not corvette) but I bought a beautiful 84 short bed silverado , totally rust free , Nice paint etc , the trans was leaking out of the front seal (350 turbo) so I built a 7000R with alto 5+ clutch packs and corvette servo , hydraulic lock up etc .. I'm putting a 12 bolt rear in it with a 3:42 gear but trying to decide about the engine .. I have a 283 on the shelf as well as a 350 and a 400... I think if I can find a used 144 charger cheap enough I may put it on ( I also want to keep the air working) but want mileage and HP. Whats your opinion ? 238? 350 with 400 crank , 400 with 350 crank ? I'm really leaning to just using the 283 with a charger . It will be a lil while on the engine build , other projects going too and a HUGE work load building homes .. But just wanted someone elses opinion..