Is there some kind of engine chart that will , let's say, convert 2 stroke to 4 stroke engines and vise versa? Some Arf's come with the engine size perameters and some don't.
If I have a .60 size plane what 4 stroke engine can I use, as an example?

Not much of a chart, and engines are all different. Here is some kind of reference point, two -> four stroke:
.46 -> .70
.60 -> .90, 1.00
.90 -> 1.25, 1.50
1.20 -> 1.50-1.80

The thing is that the power curves are different. Four strokes have more low end power, two strokes have more high end power.

multipy your 2 str ke by 1.5 for a four stroke and devide by 1.5 for a 2 stroke.