For pollution and money saving you would just get a complete ga16 motor
that will fit no problems, so you would never fit a ga16 head on a e series
or a ca16 head on an e series when the ca18 can be sleeved down to a ca16
if need be for capacity reasons and engine shop supplying receipt of proof.
The E series is best kept 8v with an e16 crank and 8v ported head.

An A series with ga16 head is a better bet for pollution free setup, cheaper
in the end than a AY with more performance potential and 3 valve heads are
available for better lower/midrange, economy and street performance.
Electric water pump or mechanical Mitsu setup is possible and as Chris says
if you can keep the oil pump and dizzie its halve the battle.

In the end Nick is right the ca18 is the best option for a pollution engine
as the gearboxes are bolt on and easier to source, replace and rebuild with
more power destroying the rare A 5 speeds. All manifolds are RWD friendly.
Then you can sleeve a cheap ca18 for capacity reasons if need be.

Non pollution
77mm bore A series with either ga16 hybrid combo or worked h89 head with full wet
sleeved block of 83.5mm bores using ca18 +.5mm pistons and a15 crank for 1796cc.
Wouldnt that satisfy most twisted A series people?

I see you point D. Sure wet sleving the a series out to 83mm and and using an e series crank to get the extra stroke is probally the simplest way forward. I guess for me its as much about the ideas and possibilities as it is about weather or not I go down that path, or for that matter anyone else that is looking at the ca, e, a series engines for a thou.

In the end, it will be the bank balance that will determine what i use, and it will probally be the a15 that i already own, but I still would like to see what sort of bitsa could me made within a reasonable budget. ie no mega bucks on huge amounts of machining for example or exotic pistons etc. I mean, with enough cash anyting is possible.

As far as the polution, I didnt consider that. Using the latter model stuf means pollution requirements to consider, which kinda pushes back to the e/a series block, but that still leaves a few options.

Still there is plenty of time to experioment.

For non-pullution we are left with the A series apart
from an early pushrod R16 from a Fairlady but they are
heavy cobers perhaps more so than the L series.
Hopefully in the next few weeks will find out about
wetsleeving prices, I dont think Ill be into an E series
crank just an 82mm stroke with 83.5mm ca18 pistons is all
Id be interested in as 1796cc should be plenty.

Lemonhead mentioned 85mm is possible which is great if you
can replace the sleeves on every rebuild or have enough meat
for other rebores or honing.

On a similar note maybe in WA if you register it as a 1968 model
you could maybe run a late motor without the pollution gear?
Supposedly that is possible with pre 68 models in some states.

You know over the years this site is probably the only one that has never got on my nerves...........until this thread!!!

Just when I think I'm content with my car, you lot start playing with parts and I think oooh a twin cam A-series would be the business!!! But wait a 1796cc A-series would be the business..........you all need to stop playing with so many cool projects. I just got the flat slides sorted now I'm going to have to build a super bore A Series or slap a twin cam on the A12, thank goodness I have my vintage MX bike to play with.

Tom

Lemonhead is aiming for 85mm bores and 88mm e16 crank so if you thought 1796cc
is the business imagine 1997cc :))) Now thats L series size with 20kg less.

Thats crazy numbers. hmm maybe that should be my side project...