what efi parts are these and can i use them on my 360 magnum

The sensor on the spacer is air intake temp. On the throttle body in the pic, the black object on the bottom is the idle air control. Looks to be gm style stepper motor. Should have a 4 pin electrical connector. It bypasses air past the butterflys to set idle speed. Those injectors would likely support 600hp or more if they're truly 50 lb hr. For example I have 44lb injectors for a turbo 318 and they're mostly too large for gasoline. I'll be running e85 later which requires 30% more fuel and they should be ok with that. You could always run stock 360 mag injectors.

I'm not familiar with haltech so I can't give any guidance on that.

I don't think the setup you bought will be using anything mass air flow. It seems it was set up for speed density tuning. Which means it uses air pressure, temp, and an estimation of the engines volumetric efficiency.