Alright, i've searched and... ran out of time so here's what i've come up with. I've got a buddy who's got a 91 prelude SI with the b21a1 motor. It spun a bearing and now we need a new motor. We're not looking for performence at all, just a working motor to get point A-b.

So, we're looking for options here. It looks like either a b21a1 or b20a5 will swap in there okay. We found a b20a3 from the prelude S motor but i've read that the fuel injection or somthing is different?
*Edit* Oh... a b20a3 is carberated sohc.

How much do b21a1 / b20a3/ b20a5 go for and what's the overall scoop on these motors?

Budget: $500-600

Thanks guys! Lend me your prelude knowledge!