Personally I wouldn't put good money after bad. The Venture system is a cheaply made system and may work okay for lightweight 5th wheels but doesn't have the power or stamina for heavy pin weights.
I replaced the Venture legs/motor with the Bulldog setup. The two systems are worlds apart as far as reliability, and power. Our Venture was less than 5 years old, hadn't been used all that much and was toast. We replaced it because it was so slow you almost had to chalk the legs to see if they were moving. That plastic gearbox is a joke. The whole thing just screams "Cheap and Flimsy".
The Bulldog has two switches so it is easy to level the legs when first setting up. But that is just icing on the cake. We have a 3,000 lb. pin weight and the Bulldog motors are almost silent in operation with no sign they are struggling in the least.
I love it, and would do it again in a heartbeat. It is what these heavy pin 5th wheels should come with from the factory.