Well, the AE 73.5mm (1380) piston are kinda high, I see Mini Mania gets like 145.00 each for them, so double your piston budget, and a little more for boring, as machinist charge a little more when they are boring more, but not alot more. A 1380 is a proven package, but what you got to worry about when going with overbore like this (.120" over) is to do you have goos block without much core shift, people taking on any big bore project nedds to be ready to accept the fact that a given block could not take the bore size, and any block work done up to that point is a loss to the customer. It's not that common, but it's something you better say to any customer who going this route. APT list the 73.5mm piston at 499.00 a set , but my buddy David, hasn't update his website in quite a while, so they may be higher now, I suggest always calling APT on prices, they are great folks, but the website is a little dated.