Piston dome height

I've banged on about this before but now have some more definitive info .............
3.5mm ish crown as std ,there's a 25T version with about 1.5mm .What's the advantage or not of reducing the comp ? 8 from 8.6 .
The piston is 8.25 and 8 across the angle to internal rad .The top would reduce to 6 but the rad area strength would not alter that much .

Also ,there is a steel reinforcing band cast into the piston across the small end and exposed to the underside of the oil scraper ring groove, darker area just visible Is this normal ?I can flex it away from the main casting now it's in two bits

Do you need a RAOC Championship Trophy Stephen ?
I could mount it up and post it to Simon

The only advantage of lower comp is a safer running engine, less likely to see detonation etc, run more boost. (not necessarily on a modified, weaker piston) The 25 T 205bhp and Lemans models run the 8:1 pistons, but its a different casting than these pistons simply machined.

The reinforcement band is quite normal. In extreme circumstances some pistons can suffer skirt flex. Its probably a standard precaution built in by Federal Mogul.