I have a 1990 F-350 with a 7.3 IDI motor it did have two fuel tanks, but it no longer does, however the selector valve is still there with the old lines plugged. I want to build a tank for for heating SVO and possibly filtered WMO. My question is can I wire the old selector valve so that I control the return line independently of the supply line. I want to be able to switch back to diesel with out the oil going into my clean tank, so mainly just wondering if this can be done with the stock sector vavle or will I need two valves to achieve this? thanks in advance for any input, this is a great website and has helped me out on numerous occasions.
AFAIK, the 6way valve switches both at the same time. The plastic Pollak valves are not very reliable anyway - especially if you have adequate heat in your VO system. The 3way hydraforce valves sold by Frybrid are much more durable and can take the heat. Many have tried unsuccessfully to use the stock-type switching valves. Sounds like you've done some good research already. The Frybrid forums are really the best place to post questions about SVO use. Not too much of that kind of traffic here! Good Luck!