hi i am looking for 2 sets of headers for a twin 496 Ho / 2001 as far as i no the E top headers should fit as they say you need 34 and half inch centers if i have measurd it correctly they should fit if anyone has a two sets for sale let me no.the manifoulds that are on the boat were replaced by the owner steve horowitz and they are made of Iron and i think they should be ally.also can anyone tell me wot the oil presure should be boat is fitted with electrice gaffrig .not run the boat at sea yet but on the hose i get 40 -44 psi cold reved the motor 2500rpm stayed the same ?if anyone can help thanks regards PAUL from england

Afaik, stock headers were alu only in the first 496s, but afterwards replaced with iron, though I'm not sure about when they switched over exactly.
They surely were already iron in 2006.
Can't tell you specifically at 2500rpm, but in mine the pressure is right at 45 psi at high cruising speeds (4000+) and 20 at idle.
When hot, that is - obviously. If cold, 40 to 45 also at idle. I never tried 4000+ with the engine cold...!