At what HP /rpm level are billet main caps and or stud girdle needed?

33IMP said
Can you tell me where to find NEW aftermarket MOPAR small block blocks for under four grand? I'm sure there are lots here that would like to know.....

I currently have 6 R3's, 1 X block and 1 Ritter block all purchased in the last 4 years so one just has to look.