Hi Sean, the 25,000 BTU burner would work, but your dryer was meant to have a two level 20,000/37,000 BTU burner 25,000 would be enough to dry clothes but would modify the dryers design a little bit but it would work.
You would need to make some modifications to the thermostats the modulating burner dryers held the exhaust temperature around 165° and relied on the tapering down of the heat because the heat never cycled off during the heat portion of the cycle
John