|Originally posted by DefEddie:|
What about the gen2 aluminum heads?
Nope... the heads and intakes are generation dependent.
Gen 1: 2.8, 3.1, 3.4 iron heads
Gen 2: 2.8, 3.1 MPFI stamped on intake, aluminum heads
Gen 3: 3100 small/large port, 3400 aluminum heads
Gen 3.5: 3500 LX9 (non-VVT) aluminum heads
The 3500 heads can be used on a 3400 but the bore of the 3100 is too small.
The 3500 upper intake can be interchanged with the 3400, but the lower intake is specific to the heads (intake port shape).
Gen 1 and Gen 2 exhaust manifolds share the same bolt spacing, but Gen 3 increased the spacing to allow for the larger ports. Port spacing remained the same throughout. You can adapt early manifolds to Gen 3 heads by slotting the bolt holes.
[This message has been edited by carbon (edited 09-13-2013).]