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If the 4 speed has the granny gear you should be fine. Biggest thing with any travel trailer is having a weight distribution hitch, sway control and a top notch electric brake controller.
X2 on getting the whole backing plate with the brakes allready on them. The little extra cost is worth not having to mess around with them. Also as long as bolt pattern permits you can upgrade to higher GVW brakes on the trailer. It will require new drums as well though. Make sure the bigger drum will fit inside your rim too.