The customer service was awesome! That's for sure a 10 out of 10! There was only 2 little issues which 1 isn't even HSP product related as much but would be great if you guys could send an instruction manuel how to put the pieces together just give ideas how to approach certain things since that would help people like me who would try to tackle this project alone and 2. It would be nice if you guys would supply a plug for the injector return line fitting kinda like WC Fab does (which by the way they do send a manuel on how to overall in general install their kits) which again no means do I mean send a whole instruction manuel but just kinda how they do in small detail to point you into the right direction how the parts should go. Besides that amazing quality and craftsmanship and I will be purchasing again from you guys soon for the manifolds! P.s. the truck these parts went on was a 2016 GMC 2500!