11mm versus 12mm

[doonboggle]

After reading several posts here and elsewhere, I still am not able to arrive at a definitive answer; so thought I'd post my own query.

I have a 81 pickup 1.6 diesel that has a slightly flawed head due to bad redrilling hole for mounting. 
Have come across a reasonable used head of 11mm bolt size.
I am not sure ... been some time since checked ... which version I have ... due to move and prolonged other issues.

So, if I buy the 11mm version, and it turns out I have the 12mm version, what would be my alternatives?
TIA

[rabbid79]

If I understand your question, the answer is yes, an 11mm head can be redrilled to fit on a 12mm block.

[sparkoid]

If you have an 11 mm head and 12 mm block, you'll have to have the 11 mm through-holes in the head drilled out to 12 mm.  Not really a big deal.

If it turns out you have an 11 mm block (your head bolts will have hex, not 12 pt, tops), I'd suggest given my recent issues with 11's that you put the new head on using studs and follow the mfr torquing instructions to the letter.  The benefit of studs is they stress the *block* threads a whole lot less during torquing, and those threads are the weakest link in the 11mm "chain".