Looking for fuel rails for my optimax ot737852, which used models will work?

[phyrefighterjay]

my opti is an ot737852
My neighbor has a 99 2.5 L OptiMax (no serial) 20” shaft like mine. Will the fuel rails interchange? Are all 2.5 fuel rails created equal?

[EuropeanAM]

Probably not, and no.

Be very careful- there have been differences in the castings, hoses, air regulators, fuel injectors, and the regulator setpoints (later ProXS models).

Since Mercury doesn't use "years"- serial numbers become increasingly more critical in situations such as this.