I use a hydro zetec in a RWD platform.
The stock single piece steel manifold shrouds about 20% of the bottom of the port in the header flange.
I realise that most of the flow is in the upper reion of the exhaust port.
Is there is "big bore" gasket for any Zetec available in the aftermarket?
The standard piece will have compromised sealing if modified.
TIA.