Godzila736

I have been looking around for a motor an tranny to drop into a 92-95 civic. so far I have found a 92 integra ls engine, tranny, mounts, wiring, ecu, and shift linkage for 400 dollars the only thing is it has 205,000 miles on it. I'm in the middle of buying it. The guy says it sifts good, and doesn't burn oil. Well I am alreading planning on doing a complete rebuild on the tranny, and I was woundering what people would do with the engine. Should I just piece it out, or should I try and do a rebuild with new pistons, rings, ect. Or should I buy a b20 block with less miles, and do a swap over. And will a b18a head go onto a b20 block?
Thanks