With a 1-6 you get a slowdown for the front and one for the back.With a 1-5 you get only one slowdown (so the front will drop a little faster than the back since it weighs more).Other than that they're the same. You will not have a problem with a wagon...matter of fact we've done these on Magnums with no problems. The Hydroholics pumps have threaded ports in their pumpheads so you can put pickup tubes on there if you need to maximize the fluid in the tank. Glad to hear you're looking to make the swap. Let me know if you have any other questions.
Aaron@hydroholics.net