Exactly thats why Im building a ca18de block with ca20e head which is what
I suggest unless you mod the ca16 head with bigger valves and custom camshaft.

You can do as you suggested but will need custom head bolts as the 8v head has
thinner and shorter head bolts.

The ca16 head could have smaller chambers which could be a bonus but Im thinking
they are the same as the ca18 8v heads.

Because youll need better camshafts there are plenty of parts from other enthusiasts
so I suggest you use any 8v head you can find peter.

Im thinking of welding up the chambers and re-shaping them to wedge shape and only
using a single spark plug on the exhaust side. Also weld up the inlet side sparkplug
area to enlarge the inlet ports in width and raise their height.
More like the inlets of the renault 807 gordini motors which had rectangular ports.
Ill put my link to my build soon.