enough with the sleeves thing already, there are 76.5 and 77mm overbores if needed, but to source only 4 of them would be really expensive.
in order to make that price Prothe bought 200 of 76.5mm, good investment or not, at this time its the best we can get.
I have 8 of 76mm (freebies), will test fit them and hope for the best
I will measure my block, if not on spec, I won't even consider the conversion, as I can get a 1.9 tdi engine for less than the machining costs of rebuilding this one.
now for the idi head conversion, would it be possible? YES
would it be cheap, reliable? not on this lifetime.
test 1.6TD head, original VW RA/SB engine
the red circle marks where the tip of the injector would protrude with stock angle (almost stock tdi location)
the TDI injector was seating against the bottom of the orifice without the fire ring. it still needs to go in another 20mm, to the green marking aproximately.
the next two are just to put it in perspective, there are lots of room for drilling for the plugs, but this is pointless anyway.
me test fitting a gt2056V on the 1.6