Z18et has the extra weight in the right place below
while CA at the top due to heavier twin cam head
z18et 15.5kg vs 24.5kg for CA18de head.

The L18 block is 10kg heavier and if going EFI in the future
can be an issue as pollution gear must go back on unless its
a rare pre 74 block which are almost non existent.

L16 with 85mm bores and L18 crank which goes straight in
is the cheapest for 1770cc, no pollution gear and lightest.
Add a light Z18et head and as Stuart says just add more boost!
Or extra $350 sneaky L20 stroker L16 for 1952cc.

Stuart wouldnt you say your Z18ET has better midrange
than most equal capacity turbo engines thanks to twin spark
pro swirl 8v hemi style chambers and LPG? :)
not to mention simplicity and economy.

Most peeps dont see the Z has some serious unmatched torque
Joe sure youre aware of Stuarts Z setup? (trb012)

http://ozdat.com/forum/download/file.php?id=19246&mode=view