That should be a 77-80 350, with windowed main webs.
In terms of building an engine for power, the windowed mains are "undesirable" because the windowed blocks aren't as strong. On the other hand, they are lighter. For a semi-stock street cruiser, it will be just fine. There should be another machined pad on the block that has the VIN stamp in it- If the numbers on the pad match the VIN, it's the original engine.
_________________
Andrew
TOC Moderator
Mark Twain wrote:
A man's character may be learned from the adjectives which he habitually uses in conversation.