What do you mean by "over square" ?

Is that setup better because of the small combustion chamber increasing te compression ratio?

what bore it out and put 2.7 crank and piston in?

my only worry is the clearance to the valves at TDC?

yer i know, but the head off the engine was fucked so was selling it really cheap,
just wondering if it would work.

Does the cylinder head switch work the other way round.
a 731 head fit with a 2.5 block, just cause ive been offered a 2.5 block and wondering if i could change it for the 2, in my 320i?

are Speedtouch's chips any good because iv'e heard mixed things about chips and why is his soo cheap?

you can get a 2.93 for really long legs lol.

from what i know the gear boxes are all the same just different gear ratios inside, so should slot right in. quote me if im wrong.

Its always worth looking at the crank bearings, if there is any signs of wear and tear they are worth replacing. Plus if you want to spend a bit more you can re grind cylinders and crank shaft for a few hundred £. you'll have a engine almost back to 0 miles but will have to run in after the re-build...