Depends on the engine in question.

In the case of my engine, i have NO idea if its needed or not, as ive never built an XE engine with a GT35R turbo and 500-600bhp before.

So as it cost me nothing but my own time, it seems like a good insurance policy.


Im sure that many of the "205 block engines failures" could have been put off to a higher BHP level if these changes had been done though, so maybe thats relevant to the forum?
But i dont have actual numbers to back that up, its only my opinion.

It WILL improve the strength of a block, but how much by is very hard to determine without a LOT of expensive experimentation! ( and i mean millions of pounds for that, its something only a mafufacturer could fund really as it would involve building and testing hundreds of engines really to be sure of the results. )