problems in my 4.6 bird!

hey guys I bought a 95 T-bird and the guy I bought it from told it me it had a dropped valve. Well I just bought it to resale, to make a long story short, this guy wanted to buy it, and wanted to try and start it up. The ole 4.6 cranked over and fired up. It does have a rattle in it but I was told it Definetly isnt a dropped valve. Can anyone advise me as to a possible cause. Some suggested a rocker arm loose..........I do not have any experience with a Modular type engine but ....if this thing could be fixed easily then I'd like to fix it and keep the car. The body is in great shape, and has a clear title. any help would be greatly appreciated.
Thanks
Ben

i'll see what I can do! the guy told me it had a dropped valve, but someone else told me its extremely hard to get one to drop a valve, that it more likely a rocker arm or maybe a cam bearing. IT definetly has a miss in it. I'll try to get a video with my camera this afternoon.

thanks

well a different guy came over this afternoon and bought the car. Since I owned it I hadnt even tried to fire it up until that first guy came over. I assumed the oil level was fine but as it turned out the second guy noticed the oil level being low, we poured some oil in it and he drove it on the trailer. Then carried it home. I had bought the car as something to either rebuild or resale, which ever came first. The resale won!
thanks guys for your comments
Ben