This same Super Connie misconception has come up a few times here at RCU and over at another board.

The issue comes down to the fact that the Super Connie has a rather high aspect ratio. This severley cuts into the wing area of what appears to be a LARGE airplane due to the span but in reality is only a medium size model thanks to the wing area. Your best bet would be to forget about the span and start by looking at how much wing area it has and then compare this to other models of the same wing area and figure that you will need to keep your weight down to the same amount. From that point you can then figure out what engines should be in the model. Any model flies first and foremost on the wing and if it's heavy adding more power will just produce a model that arrives at it's own crash site that much sooner. I'd suggest that you determine your wing area and then study other scale models of that same wing area for loading and power requirements. I think you'll find that the Connie will need to be built very light to keep the wing loading in the ballpark. Probably something like 10 to 12 lbs. At that weight each .25 would be lifting 2.5 to 3 lbs. Something that these engines are able to do easily and in a fairly sporty manner.

By all means scale the model from the plans you have but toss out pretty much all of the balsa and wood sizes and types in favour of a more suitable internal structure. U control models of that vintage were almost all overbuilt by quite a healthy, or rather unhealthy, amount. About the only things you can use from the blown up plans are the fuselage bulkhead shapes and perhaps wing ribs. But even those much be modified to deal with a thinner and more appropriate sheeting size for the fuselage.