A reed valve engine that has two bypass ports in the cylinder will have more power than the single bypass found in the classic old Baby Bee and Golden Bee. A Black Widow as well as the currently (at the moment) available product engines have the twin port cylinders.

The TeeDee will pull the GL up fairly nicely but it's more of a steep uphill glide angle rather than a serous climb. The BW or product engine reedies will glide it uphill at a slightly shallower angle but will manage if it's not much more than 30 oz overall.