86 Silverado Father and Son project

[mcbassin]

I'm working on all the mechanical issues with the engine install. But, I am starting to try to figure out some of my wiring and gage problems. I'm curious if any of you guys left the original sending units if you did this type of swap? I am planning to install the original truck oil senders and the temp, I just don't know about the ones from the car engine? Does the ecm need to see info from these? I will have to come up with tees if that is the case.
Here is the car senders:


Here are the truck senders:



I also notice there are some electical components I don't know what are?
I know one of these is a fuel pump relay....so what are the other pieces?
do I need them?