90 91 CRX with SIR knuckles will they fit Use Karcepts P/N: KWH08 for a custom 36mm USDM ITR 5-lug EF/DA conversion. These hubs are identical to our KWH05 hubs with the exception that the bearing journal is cylindrical ground to DA (USDM 1990-1993 Acura Integra) specifications. These hubs can be used for 5x114.3 conversions on EF/DA chassis per information provided here. However, please note that these hubs can only be installed into USDM 1990-1993 Acura Integra knuckles. So if desiring to use these hubs on a 36mm 5-lug EF conversion, you must also need to utilize DA knuckle assemblies into the EF chassis. These hubs use a 42mm I.D. wheel bearing.

and will CRX SIR knuckles fit Drive Shaft Shop's CRX B series PRO-Level hubs and axles?

The Pro-Level Honda/Acura systems are made to withstand the demands of the highest horsepower drag cars and can currently be found in the fastest FWD Honda's to date. Our Honda/Acura Pro-Level kit is a full drivetrain system that includes both axles, featuring our Porsche-style 108mm inner CV joints and bolt-on axle flanges, our signature 33 spline outer CV's and the larger hubs to accommodate them. The most significant part of the Pro-Level System is that we are replacing the standard 27 spline differential spline with our 40% larger 28 spline transmission spline plug and intermediate bar, for use with the DSS 28 spline Pro Limited-Slip Differential (DSS Pro-LSD sold separately). This system includes all the hardware necessary for the install and comes with our full 1-year warranty. And if you already have a set of our Level 5.9 axles, they can now be upgraded to Pro-Level axles for much less than purchasing a new set. When you're ready to go for records and challenge the biggest names in FWD drag racing, the DriveShaft Shop Pro-Level drivetrain is the only way to go.
This is drag race-only application made to withstand over 1000WHP.
PART# AC28

This system does not come with ABS Rings. The rings can be installed for an extra 100.00 (not discountable)
Please note: The Level 5.9 hubs are made for 90-93 Integra knuckles. If you are using these for a 88-91 Civic, you must change the knuckles to the 90-93 Integra due to the wheel bearing size.