750 vs 850 vs 950 Holley

So you're opening the throttle blade to about 7° before 90° ?
I have used the China base plates, and they are poor quality. The last one I used had different length transition slots, and the vacuum port nipples were so crooked they looked as if Ray Charles put them in with his feet. I won't use the China knock off base plates anymore, too many issues to fix for little money saved.