I am currently Restomoding a 67 Camaro RS. What is the cost to rewire car from front to rear including cost of wiring Harness ?

 

Restomod with a carbed engine or an LS conversion? Makes a lot of difference what you plan on doing with the car.
Depends on who does it,DIY or paying someone,parts can be sourced a number of places so do your homework on that.
https://www.painlessperformance.com/

https://www.camarocentral.com/Camaro...es_s/41000.htm

 

I am installing EFI on s small block 327

 

Should be pretty easy,lots of kits out there from folks like Holley.
The rest you can find in the links I posted I'm sure.
Put some pics up when you can'we'd love to see your project.