Well the hf and si crossmembers are the exact same part. If you're asking whether the hf's crossmember will make more space in the bay of an si for the b16a to fit better, no it won't. I don't remember having to bend the front crossmember on my crx for my b16a to fit right, but then again my car's previous owner had an accident which bent alot of front end parts.
As far as the steering parts, they are also the same.