360 magnum questions

Hi everyone....will a 360 magnum bolt up to the motor mounts just like the older 318/360? Will my spitfire headers fit the newer heads? Also will a 904 bolt up to it? and last but not least, will the j heads I have bolt on to the block without issues? I am getting ready to start a 360 swap and I have found a couple of good deals on the 360 magnums. I also have a 73 360 shortblock I can rebuild. I think it would be cheaper just to drop a slightly used magnum if it will fit.....(it would be carbeurated) Oh yeah, Are there an other concerns that I am missing? Thanks for any help.