Greg - I was so big on this a few weeks ago. Spoke to Jason @ Katech, Gary @ ARE and Bill @ Aviad. I also posted a thread on 'Tech and got some good opinions. My situation was maybe a bit different as I already had a ported LS9 pump, Peterson tank and baffled pan. None of which I was relishing swapping out. BTW, (FET) Mike Maier is running a tank in the trunk and Brian H was very helpful in showing me the set up.
General concensus with the experts was it could be done w the factory pump and tank, but would probably need -16 feed/return. ARE suggested I use their pan...
Here's what killed it for me. First, I can't reconcile how a -16 return gets fully utilized when my thermostat, cooler and other parts use -12 and smaller? I kinda thought that must defeat the purpose, or at least create a fluid bottle neck. Second, have you priced -16 XRP fittings? One bulkhead pass through needed four, maybe eight ($800). I didn't price it out completely, but I figured I had $1200 or more in fittings for those two lines. Third, packaging it on my car was another fab item to add to the list. Take my word for it, we eyeballed it front to back and there's trunk work, pass throughs to ensure the lines are not the lowest thing on the car, and possibly subframe mods to get it to the pan. That's getting old w a painted/powdercoated car, and I've still got a long list to complete; I want to get my car on the road at this point so it was a question of priorities. Fourth, thank Hollywood for this, even w a firewall you're putting flammable fluids in the passenger compartment of a car that will see street time. Carl and I both agree (you guys may not) that even though there would be a firewall separation, the trunk is part of the passenger compartment. Fifth, everyone I spoke said there was no significant front end penalty with tank up there. Lastly, I'm not building a max effort race car. My car is a street car that will be track capable. It may see more track time than street time, but it would certainly be a different animal if it was track only. I don't know how to better explain this, but putting the tank in the trunk would violate the theme of the car. I could go further on this point but this is already the longest post in Lat G history...