Engine re bore

Manged to source a spare engine after I cracked the cylinder head when it over heated, the 'bad ass jet' will be back on the road soon. Now I have half an engine that I am wondering what to do with, thinking of stripping it and having it re bored, believe the current bore takes a 76.4mm piston, anyone know what the biggest size of piston I could have it bored out for, suppose it depends on how much the head gasket bore seal goes upto. I was quoted 25plus vat to re bore and hone each cylinder, which I didn't think was bad.. Any thoughts on this kinda mod would be appreciated

If your thinking of 'modified' hijets, from memory the 1.6 "HF" engine from the sportrack and the charade 1.6 gti is the same family as the 1.3 hijet, so maybe having parts to compare with could make 100 bhp hijet on the cheap