I just got a 91' prelude si with a b21a1 I believe. The motor is no good (save the heads/intake etc) and I need a replacement. Any suggestions on compatable engines or websites?

 

ebay is about the best place

 

ebay or Evan's Honda Salvage 423-623-8781

 

Would a b20a5 be a wise choice? If so, what would I need to do to drop it into my 91' lude?

 

So how many "Heads" does your motor have?

I like Hmotors.com

But a compression tester and someone hard up for cash will always surface.

Always try and test the compression if someone is going to sell you a motor with no guarantee.