Question about 5.0 motor in 86 GT.

[eeh102582]

Hey guys i bought this car from my cousin and he had this car since 88 he bought it off some and my cousin did know anything about it, HERE MY QUESTION, i been seeing what evey body has been saying about how much HP these motor should make with mild work, and there puting like 270 to 300 thats with alot of aftermarkets, so i took my car to get a dyno, now its an 86 GTHO motor, the first place i took it to i got 280 on the dyno so about 5 miles down the road i took to another guy that i know and on his machine i got 282, now he says that it might have some work done, he says it looks like it was taken apart because there is the orange rubber gaskets used to seal everything, ford uses cork, IS THIS CORRECT.
thanks alot
Ernie