I have always had good results with the 280-.474 cam in big blocks.Decent idle and the power comes on sooner than the larger cam profiles.Don't need any more than a 3.55 gear either.Sure there are "better"/newer cams out there but these still work.If you already have one then use it.If not nothing wrong with looking at other brands.
I am sure the .508 didn't like the 3.23 gear either.Your converter would be a good match for the .474 or equivalent cam.
