How much can a thicker gasket decomp an m20?

[The Humjet]

I am planning to put a 2.7 engine with a combo of an eta block and a 731 head, now I know this combo is a good for an NA setup with it's high compression ratio.

Now until recently I decided to go turbo as I saw the WHP figures on a NA 327i and it wasn't as high as I thought it would be, so turbo is the way to go.
But i need to decomp my engine and someone suggested getting a thicker gasket could work, but I think it's best to ask you guys on how to go about this.

I know the best way to decomp an eta is by putting an 885 head on, but down here in Australia they're not cheap costing $750 just for a 2nd hand head unless I can do a part exchange for my 731 head I have sitting at home which isn't likely.
Could I shave back the pistons, or as dodgy as it sounds someone said to stack two gaskets ontop of eachother.

Or does anyone want to swap an 885 head for a 731?

What would you do if this was your scenario?

[blueapplesoda]

you can try shaving the piston crowns to take the cr down a notch, whilst running a slightly thicker cyl head gasket. should put you back around the 9:1 area at least, and thats pretty decent for turbo.

I'd say cheaper route even at $750 to go with 885.

what is your power goals? cause 885's here are a dime a dozen. just buy one from someone from the states.

[The Humjet]

Yer I heard they are pretty common over in the states but postage is very expensive. But they're also not rare over here here in Australia they just like to bump the price on 325i engines for some reason. A m20b25 cost about the same as an m50b25. But with a bit of hard searching I could could find one at an Ok price and sell my 731 head for a bit of cash. I only payed $80AUD for my eta bottom end so I have save some money there.