M96 and M97 - to what extent are parts compatible?

Context: I'd (potentially) like to use parts from the M97 for my engine build, as (for example) the X51 intake for the M96 is NLA.

From staring at Google images my belief is that you cannot use the M97 intake on the M96, but it would appear that the exhaust manifold can be used across the two - which would be handy as the 3.8l X51 manifolds are available.

Does anyone know for certain?

Excellent question opcorn:

GT4 is very knowledgeable on subjects like this.. sadly I've not seen him post for a while :dont know:

the 997 x51 manifold looks just like the stock 3.4 manifold...but is it fatter at 48mm?

i heard the stock 996 header a better design than stock 997, again not sure on diameters.

these are 997:


I read the exhaust is interchangeable.

You just need to reposition (weld) the tail pipes to suit the bumper.

I was hoping to keep my Cargraphic exhaust and make any required adaptations in the (likely) top gear 200 cell cat sections.

I think diameter is very important to the manifold- flow bench tests on a tubular, equal length manifold of smaller diameter showed a surprising restriction.

Message from an eBay seller with regards to an intake manifold:

Yes. The bolt patterns are the same on all m96 engines. Boxster 996 997 and so on. The manifold will physically bolt on, however you will have to change and or modify a few brother hoses and such but that's it.

Which I'd love to be true.

This does look very similar:



However note the zig-zag pattern of this 987 manifold:



Which looks to me to match the upper face of the M96 intake runners:



The underside of which looks like this - a straight line:



The orientation is based on where the injector goes - I'm making the assumption that it faces down into the head (which seems reasonable, but I'd love to be told I've made a mistake!)

Have I missed something, or is the eBay seller wrong?

Just to close this out, I'm satisfied that the M96 head is not compatible with the intake from the M97.