The dyno tests of stock iron-barrel models show about 14-15hp at the rear wheel with the 4-speed gearbox(grease-filled), and about 15-16hp at the rear wheel with the 5-speed gearbox. The 5-speed gearbox has lower transmission losses.
72Westie did a dyno run on a new Electra X AVL and it had similar power level as the iron-barrel, about 16hp at the rear wheel.
Both of these engines can get up to about 20rwhp with a free-flow exhaust and carb re-jet.
The stock iron barrel peaks hp at around 4300rpm. It peaks torque around 3300rpm.
Those peak rpms go up by a few hundred rpm, in both torque and hp, with the better exhaust and new jets.
I don't have those figures for the AVL.
72Westie also ran a new stock UCE on his dyno, and got about 21hp at the rear wheel. I don't know what the rpm was. I do remember noticing that it had a very broad torque curve. Each engine will vary a little bit in dyno results, so that would account for some difference in the MCN dyno test, and 72Westie's dyno test.
So, those are some real-world figures that are actually seen at the rear wheel on a dyno test.