Here's a link for the serial number decode http://www.yearone.com/updatedsingle...gineinfo3.html page back and forth from this one for other clues.

The block casting number should be back near the bellhousing mount area on the block.

Those heads are 86-88 efi heads, not particularly known for "high performance" applications. Both my charts didn't show cc for them, but are probably low 70's cc.