It appears I still have the original style lift pump and I want to go to the FASS system. The only question I have is the OEM fuel filter housing has a fuel heater in it, the FASS system no heater at all. Will I have problems when the temperature hits -43 Celsius and at highway speeds, any heat build up is wicked away? I use good diesel from the Flying J and use DSG winter fuel additive.
Thanks.

 

I found this on MWFI. http://www.mwfi.com/winter/FuelLineHeater.htm

 

Your fuel is warm at highway speeds. If your truck never shut off, I'd venture to say #2 would flow till -15*F. Last fall when I was driving through Montana, I filled up in Utah and we had not yet switched over to winter fuel and it got down to -8*F around Dillon. I was worried but looked at my fuel temp via Edge Juice and it read 48*F. I was driving around 65-75 mph depending on road conditions over Mallad Summit, but what I'm getting at is that when truck is in use, it recirculates a lot of fuel through the VP housing which is quite warm, probably 150* or more.

Now when the truck is off, that is a different story! But if you garage your truck or run a good antigel, I don't see why it would be a problem.