2.5 block sizes

[Simon13]

I've heard that 2.5 blocks came in two sizes.

I want to start to build my 2.7 end up as i might fit it to the auto i have seeing as the alpina is such a hoot to drive.

I have the block but i think it's too far gone. I'm guessing a tape measure won't be accurate enough?!

I know if i build the bottom end complete i can just fit it to a 2.5 head and line the crank and cam up at TDC and off it goes. No need for block decking or vernier pulleys. Would make a decent drive i think