Are you looking at U2LSS racing? or other class? or just building a cadet for other duty?
The ca18det blocks has the oil piston squirters which can also be retrofitted to any CA motor.
ca20e block has thick cylinder walls, thicker than most first ca peeps believed as although tall the material the L series has on the skirts is on the extra height and thickness of the casting of the CA as it has no skirts but can be strengthened using the ca18det ladder brace or a custom one like this....
Ive come across info from an old ad advertising a ca20et for speedway that it lived at 9500-10,000 rpm with methanol with 25 psi reliably.
Some peeps have also done the ca20de with good results.
Using a ca18 crank into the ca20 block works with evo 4g63 rods "OR" the crank I have with Nissan Z22e rods for much better rod stroke ratio and extra capacity.
Pictured here is the clean webbed ca18et block (as opposed to the more webbed ca18det block) same webbing as the ca20e but slightly lighter due to shorter height. The Poms are getting over 320hp with 8v head.