Shouldn't make that much difference though. The block is the same and the only differences between the 250 and 230 are the head, turbo and boost pipe routing. I ran a 250 turbo and a ktec induction kit. The expansion tank at the rear like others and as Wilson points out the same intercooler.
It was running stupidly low inlet temps.
Read that forge said the 250 runs hotter than the 225 when developing their IC. All the conversions are different, I've seen Ste do exactly the same yet run into a completely different set of issues.