L series would only have a strength/Reliablity advantage over CA. would still be taller and heavier i'd imagine

Also, its not a bolt on situation to get a Z head only an L18, as there is no bolt on timing cover as all the Z's are the height of an L20b. Not the hardest issue to get around. but its more of an issure than bolting a Z head onto an L20b

No pollution gear has been my pube-brained quest for years.
It was either that or at the local then using the gutter as a pillow
which would've been more time successfully on the road than w/ the car.

Ill get you the facts any moment now as Ive studied, weighed and measured
the Z18et head vs the CA20E head extensively.

I was going ca 8v head as its about 5-6kgs lighter than 16v not to mention
narrower and has more torque with all things being equal to 5000rpm which is
perfect for the street. However when i stripped the Ca 8v head and started
porting it and seeing how crap the casting is, I pulverised it with a steel pipe
I keep incase someone tries to jump my fence.

Now its either the ca18det or L/Z18t hopefully will know by tonight or tomorrow
when Dave on another forum weighs the L18 bare block. The only issue is the
l series rear is wider than CA due to the skirt on the L but an L18 block
with 87mm bores and its better crank choices has confused me again.
The Z18et head is only 1063gsm heavier than the ca20s head and the Z head can
be lightened further using later alloy rockers instead of the cast steel ones.
Its anal I know but theres no medicine thats worked yet.

interesting... so what L bottom end is the go then? i have a set of sr20 86.5mm forgies, are they able to be shoehorned in so some real boost can be thrown in?

D your brain must keep you awake day and night! haha

Ok Daves got back to me & he has weighed the bare L18 block w/ maincaps at 37kg. CA18de w/ sump no main caps 39kg, 2.5kg for sump makes 36.5kg add maincaps & wala! 37.5kg....wait forgot ca18de ladder brace is about the weight of sump!. On even par would be the weight of a ca18 vs L18 as both have non full c-weighed cranks so the 5kg heavier l18 could be from the older heavy starter & beefier crank as far as I can muster?.

Edit:
Lags, only issue is the "L" is wider than CAs so dont have an L to see clearances in this part. However the Z18ET head is 11.8cm tall exactly & block is 20.71cm from crank centre to deck height (20.51 CA) yet the skirt & sump combo on L series is less than the CA with deeper sump due to longer stroke by -1cm. L and CA-DE heads are much taller about 18cm for the L from memory (DE Nick will know). However you should have a CA for your 1k to compete with the SR in your 1600 to see which is more fun :))
Ive got a ca16de block (plenty of meat for 84mm slugs) for a DET engineering capable setup and the L/Z will need to be an L16 for starters (will need dry sleeves).

As for me scone it turns off really well round the inlaws ;)

just weighed a bare a12 early block with maincaps
at 30kg, only 7kg lighter than an L series block.