Yes a very common mod, has been ever since supply of genuine T/C blocks started to dry up. Using T/C pistons, 1600 rods and crank. Requires a spacer above front cover and 122 tooth chain (though a 120 tooth can be made to work).
Burtons, yes, or elanfactory.com.au in Vic if you want to buy locally
See weblink in title of reply, a useful read