I recently purchase a couple of HP500 which by serial # are 1995 vintage they were from a 1995 42 Fountain that was purchased new in early 1996 and was a one owner boat.
The only work the owner did to the boat was valve springs in one motor. One of the motors was sealed.
During dissassembly of the motors they have I think crane gold roller rockers and a roller camshaft.
I was expecting a hydraulic lifter not roller camshaft am I wrong?

HP500'S have hydraulic roller cam's

looking on mercruiserparts.com under the motor serial numbers they show up as 1995 HP500s with non roller hydraulic lifters
http://www.mercruiserparts.com/selec..._nbr=809431+94
Would fountain have changed them?

you sure it's an HP not a Bulldog, I am looking at some motor's a guy said were hp 500's but they are 540 Bulldog's.

If your just looking at the pictures, yes
they look like flat tappet lifters,
mercruiser parts pictures are very
vague, go look at the cylinder heads,
they show a small block head in the
picture.
What color are the intakes ?
Blue = HP500 502
Black= 500 bulldog 540

Bulldogs have flat tappet hyd. cams

I have never heard of a flat tappet
HP500, the HP465 was a flat tappet
502 , the HP500 replaced it.

is there a web site that has Merc motors by serial number
on the mercruiser parts site It show Bulldogs and HP500 with serial number that could be the same