1992 Z34 engine oil cooler problem

[sspeedstreet]

I installed one of the factory water/oil coolers on my crate motor I'm installing in a Fiero. I'd read on the board they are prone to leaking, so I bought a new cooler-to-block O-ring and torqued it all to the factory 22 lb/ft.

It leaks like a sieve.

Googling the problem I came across a gasket set like so:



Should I be using this gasket as well as the O-ring?

Thanks, Neil