There was a better style intake seal that did not require machining. I recall late 70's small blocks. However, I was unable to get those. I ended up using the umbrella type on both intake and exhaust, as shown above. Indeed, I got a spare set since I thought I was ordering the former from Autozone (based on photo and year), but received the umbrella type. That is a common problem, you order and it is a crap-shoot what you get. Rockauto seems best in showing what you will really receive.
Re will they work. Sure, they were the original design. What probably matters more is how tight the valves are in the guides, especially the intake where oil can get sucked in and give a puff of blue smoke when you leave a stoplight.