OK New to Toyotas and I need help...

Ok. I am re-doing a 2000 Taco with a 2002 front end with 4x4 front fenders on it. It also has a 93 rear end in it. What size backspacing do I need for a 20x8.5 wheel. Please help. Thank you.

I'm rinnin a 20x 8.5 with a +35 offset and tuck just fine....mine is the pre-taco but that should still work for yours

so what would that be in inches from the inside rim to the wheel mount? thank you for your help.