Can bigger intake manifolds be put on a 3.2l?
 

I was wondering if there is an after market intake manifold available for the 3.2S I thought I saw a cayman manifold on a boxster before?

i'll bite - are you talking actual manifold, or plenum and/or throttle body? there's a diy on planet-9 about putting an x51 manifold on a cayman, but it shares heads w/ the 3.6. ipd and softronic do the cayman and gt3 throttle body and plenum thing for the 3.2. uncertain about actual manifolds, however. uncertain if the bolt patterns on the heads are similar, resonance configuration works the same, perhaps clearance issues, etc.

The only intake manifolds available are made by Porsche for the specific application. You don't want a larger manifold unless you increase your displacement. 3.6+