Well I took out my wore out 175s and put in a set of used 215s, along with injector install kit.Now it seems weaker, pops above 2000 rpm, and runs about 10 psi lower on peak boost, was 38 now struggles to get to 30. Any ideas or might these injectors not be good?

 

Seems like a fuel starvation issue or getting air into the system.. I would re-check all the connections to/from the injectors and fuel lines that were moved in the install. If the 175's worked, the 215's should perform the same.