4064 is pretty slow burning. I like to use a chart to get an idea of what kinds of powders I should be using...
http://accurateshooter.net/pix/burnchart1601op.png
Anyway, I have shot 4198 and Varget through my 45-70 and I much prefer Varget. Your 4064 is closer to Varget than 4198... For cast loads with a 405 grn boolit, I do 40-45 grn (I like 42) and it is stout but accurate. For GC loads with a 405 grn boolit, I go up to about 50 gn - if you go to max (54-55 grn), each grain above 50 seems to add a magnitude of recoil. Also, I found that about 52-53 and above was a compressed load with my boolits.
The thing I found with 4198 is that it has a sharper recoil where as the slower powders have more of a push recoil...