Sirion 1tr into 2000 model cuore

before I start looking more into it of hunting one down
does a sirion ej go into a cuore without many issues
as the sirion are more readily available than the cuore

Will bolt up and be simple that way. Others will be able to tell you for sure if the looms are interchangeable. I think they are. I’ve got looms from both which are identical, however, I’m not sure if some years varied in that regard. If you have a head that has an oil return down to the oil filter block then just make sure you stick with a replacement that has that. Check the inlet manifold is the same as yours, there are a couple of different ones I’ve seen with just the slight variation on the water jacket beside No1 inlet. Some are blocked off and some get coolant for the heater from there.