Cup 255 intercooler.

Just came across this intercooler on the Lotus sport PDF. RuleWorks, Part No. - BLS3E0169F
In what way does this differ from the standard cooler is it just bigger or different core? and why did they not fit it to the later Cup 260.

Bigger intercooler, also fitted to the 2-11’s.

Not sure why thye didnt use them on the later cars…