Magnum 360

Hi this is scott, I wanted to ask some questions as I know vertualy nothing about the Magnum V8s, I have a 1973 Roadruner that has a LA 360 donner motor in it for quite some time withch has a very slight rod Knock. I pulled the Numbers 340 out for a Stroker build. I have every thing for that motor besides the Push rods and ballencer. Ok the question is I have come across a Magnum 360 rebuilt to stock specks, 30 over, car pan, Eddy manifold and carb, 360 pullies, and a rebuilt 904 trans, for $1400. The 340 would be grate to have backi in but the plug and play of the magnum is a nice option? What is the going rate for a rebuilt magnum? can I use my 727 trans, will the B&M falf moon flex plate work on the Magnum? I have alot to learn. Thanks Scott