My 340 in my 66 developed issues :-(

Not sure what's been done to that engine but it looks like the intake fit was terrible. That mayb have contributed to pushing the gasket out. I'd look at fixing that since you're in there.

I'll tell ya, the car went very nice and had a nice (mild) cam sound. To anybody who don't know what a muscle car is capable of, they would think it was a scary rocket! But I know there is so much potential... If that head gasket didn't blow the other day, I would've run the car the way it was till I have it paid off but since I have to break into it, I'm building it:-) I think the guy who built it did a nice job..but it wasn't me and I love to know my engines in and out. As a matter of fact, if I had the money, I'd pull the engine and go through the lower end.. But the bores look nice w/out a wear ridge, it didn't blow smoke, and my oil pressure was good.. So I have confidence in the lwr end..