My engine is toast

[BYprodriver]

Originally Posted by PaulE

The 3.6 from an 02-05 996 will “bolt in” to an 03-04 Boxster S. But to get the 996’s 320 HP of the 996 you need improve the intake and exhaust from stock Boxster S and had the ECU flashed to the 996 tune, according to what I’ve read on the inter web which is never wrong. The 996 intake manifold works if you lower the engine or maybe modify the engine cover and don’t care about your rear speakers etc. some of the engine ancillary things like the oil and cooling fillers need to be changed to the Boxster items and the intake plenum and cross over tubes are reversed on the 996 vs the 996. The exhaust manifolds need to be swapped for headers and the system opened up from stock. That’s what I think I know about it.

This would be the best end result, I have a 2002 3.6L case & many of the external bolt on parts to do just this. I'm pretty sure you can use the original 3.2 heads to keep all the bolt holes in the right place. Have the engine resleeved with larger cylinders to make it 3.8-4.0L.