If you can find one for sale, I recommend you go with the redesigned all metal Hell Gate bridge #305, which has several improvements incorporated into its design. For example, its has been "widened" to the point that two parallel O gauge tracks can now run across it, whereas the original could only handle one track. Unfortunately, the above rail height has not been increased so while you can run wider trains through it, you cannot run taller ones. Checkout this posting for all of the #305 specs:
https://ogrforum.ogaugerr.com/...efinitive-comparison
Bob Nelson