I recently did a complete electronics swap on my Carvin B4.
So I've got two HB4's for sale. They retail for $80 so I was thinking $45 shipped for each one or $80 for the pair would be a good price.
I've also got the Carvin pre that was removed. I'm hesitant to sell it because I didn't do the work myself and I can't say for sure that it is in working condition. It is the standard Carvin pre that came in the B4 (2006 model) if you opted for active electronics. 5 knobs for volume (pulling up on this put it in passive mode), balance, bass/mids/treble and a switch to split the coils.
If someone buys either or both pickups, I'll throw the pre in for free with just an extra $5 to cover shipping. Again, this is being thrown in AS IS.