Question about wheels and drop (sorry I'm new and australian)

[TJ.]

Hey guys, I'm very new to c10's, it's been a dream of mine to own one of these for many years. I finally found a decent one and bit the bullet. I'm from Australia so it's going to be pretty great to have one of these driving around, they are super rare!

Here she is



Now the end goal is to make it look like this one pictured below, except an inch lower at either end.







Okay so here is the problem, since I have no experience with these trucks. I had/have no idea what to actually search for.

I'm sorry if all of this stuff has been repeated, I've maxed out the search button on this forum several times over haha.

It's taken me a few weeks but I've learnt that those rims are Rallye 15 x 10's.
Now what I want to know is; will a 15 x 10 with 5" back spacing (I'm assuming this is offset, we measure it in millimetres over here) fit on the front? Or will I have to go with 4.75" back spacing? And I was planning on using a 255/60/15 tyre all round.


My plan is to go with a CPP 3" & 5" drop kit. I've read in a few threads on here that the drop spindle pushes front hub further out, is this true?



Thank you and sorry again if this question has been asked a thousand time's before, I've tried searching and just keep getting different information.