The workshop manual for replacing the head on a 3.8 E-Type Engine states that one side of the gasket is marked “top” and this side should face up. I can find no such marking on either the old or the very expensive new head gasket. Are the new gaskets reciprocal?
All I can think of is the verse:
Poor little upside down cake
Troubles you’ve got 'em
Because your top is on your bottom.
This was only true with the old thin metal gaskets.
Modern new gaskets do not have that anymore.
Dear Peter Jan Rusch,
Thanks for your help. My new gasket is very fancy and looks like it will seal very well.
Thanks again.
Lowell Brown
Modern 4.2 gaskets have a barely legible „TOP“ stamping on the side between the 3rd/4th piston - if the coolant jacket holes were larger on one side they would go on the exhaust side - if none of the two I don’t see a problem with orientation.
The modern gaskets are fancy, cardboard with metal rings around the bores and rubber sealant around all the passages; they do look nice.
What is the fancy new one, a Cometic? Is it composite or metal? I think the only time it would be sidesy is if it has raised metal sealing rings around the cylinders. In that case, the raised side goes up.
My 3.8 got a slightly oversized composite Cometic last year and it was not sidesy. Do yourself a favor though and used sealant very sparingly around all coolant passages and around the front timing chamber. By sparingly I mean daub fingerprints of it lightly around all the ports and around the front, then place the gasket and do it again on top of the gasket. Work fast so it doesn’t set.
“Sidesy”. 
I like it!