You don't think the way you have the return lines so close to the head(maybe even touching) that you will still have the same problem with higher fuel temps? Of course the head won't get as hot as the turbo downpipe but it still gets pretty hot. Just asking.
I don't think those lines will get any hotter than the fuel rails, which are probably just as hot as the front of the heads. The front of the engine bay gets way more airflow from the fan than the area near the firewall. I haven't had any hot fuel issues so far, so I'm hopeful I'm okay.
So I'm late to this thread, but the vacuum issue you spoke of a page or two ago.
Powerblock Horsepower just had an esipode on a 76mm turbo' 347 using a Jones serpentine driven vacuum pump. I'll post the link, maybe it will help.
Black & Blue: Stage III | Engine Power | PowerNation TV - Full Episodes
I'd love to run a pump like that. Bolting it up is the issue. I would probably need to make a custom bracket that puts the pump where the a/c used to be without lowering the power steering pump. Damn turbo piping making everything difficult.
Once I can get my hands on some 116 octane fuel locally, the car will be going back to the dyno for what I hope to be some big boost and big numbers.