I think the deck is usually tilted slightly so the front is higher than the back. This may be partly to reduce the number of wheels needed, but I think it may also be because such tiny wheels on the leading edge of the deck might cause dig-ins rather than cure them. It might be worth trying it with a temporary rig rather than welding everything in the first place, in case you find it pole-vaults your deck and you have to take them off again. It will mainly depend on the size of the wheels, and the compliance of the system that holds the deck up.
While you're working on the chain, you might clean and dry-lubricate it, and check it for wear. A worn chain ruins sprockets.
