[FFR428]

Sure you can check the vin number and engine tag but you really have no way to tell other than pulling the head and measuring the bore as woods428 advised. What condition is the car in? If it's not a driver and really just good for the engine the seller should not mind the head coming off. So feel him out and try to get some numbers off the heads and intake too. This will help ID what is there. As many parts can be swapped there is a good chance it might have been done at some point. Take a look see what he has and says about the car. Post some of the numbers you can find. You might have to crawl around the engine a little to see the block numbers but they are there. Where are you in CT? Glenn.