Just found I probably have a 2.5 head on my 2286 3mb block.

Is there an easy way to confirm this...? The glow plugs are M12 (yes, I have bought M14 plugs which don't fit ).

I'm having the hot spots and valve guides replaced and don't want to keep buying parts to see if they fit (my 2A parts book obviously doesn't have the numbers).

Any other consequences of a head swap? Did 2.5's have a different CR? Injectors the same?

Any info would be great, as some of these franken-engines are less well documented.

Thanks,
T

hot spots and glow plugs differ but you can use either head, injectors are the same its a flat head so cant effect cr,bores are the same 2.25 and 2.5 ,only thing you need to watch is later heads are metric early imperial threads,doesnt matter to fitting just watch out with rocker shaft fastenings and manifolds ,later 2.25 heads had later glow plugs like 2.5s ,you can tell by position of slot in the hot spots for securing pin,top pic is early 558168 slot is directly opposite port,bottom is later err1223 slot at 2 oclock

Thanks James, excellent as usual.
Pins at 2, so later type.