355 EXHAUST MANIFOLDS
When my 355 was about 4 years old with about 40,000K the RHS Exhaust Manifold cracked.
The dealer (in Australia) quoted about A$15,000 to replace with factory parts.
I decided to repair it for about $2,000.
This did not last long...and when I took it back to the dealer he told the LHS was also gone!!!
I was at this stage tempted to go TUBI for about A$9,000.
I decided to repair them both once more, this time by top quality racing car exhaust experts for about A$3,000.
So far the results have been good.
The dealer told me the repaired exhausts are now better than the orignals.
The dealer also said this was common in 355's especially the RHS.
They said it was heat related, that the pipes are thin and very close to each other and when the get hot they expand, touch each other, fuse together and then crack as they cool down again.
Hope this is helpful.
Would appreciate any comments.