273 4 barrel manifold questions

Will be going to swap meet this weekend, and will look for sp2p or ld4b(preferable). What should I look at as far as condition, modifications, etc. Found this for port size, is this right
1966 - 1967 {273} Casting #2658920

Heart-Shaped Combustion Chamber

Factory CC Level..........................62.0 to 65.5 CC's
Recommended Minimum CC's......57.3 CC's

Intake Port Gasket Size...............1.05" x 2.07"
If I don't know what I am looking at I as least want to look like I do. Will assemble a small tool kit to take with, small flashlight, calipers, small brush, anything else that might be useful?
Also do I understand right that a d4b can easily be made to work on my engine?

Thanks
Aaron