Help with engine id numbers

[honda449man]

Hello, Ive been all over this site lately, and its great. I need help identifying this little engine in my truck. 84 ranger-I was told when i bought it ,that it was a 2.0 from a mustang.Single barrel carb. im looking to go from a 1bbl intake to a 2bbl intake and I am aware of the diffrence in port shape. So without removing the intake manifold, how can i tell the diffrence in head and block sizes. Can you tell me where the casting numbers are on the block and how to decode them? Ive looked in the search on here, but had no luck. Thanks