I've just spoken to Radtec about this and have been told the proper WRC cooler has a special aerospace core and it will be no benefit in going thicker if a gen core is used, Tommy Field uses them on his car and you can't get better. The cores have limited numbers, hence mines been reserved.

But if you use the industry std core ie like the ones use for the RS500 yes thicker could be better.

If you want a gen cored one they are old stock so the cores have been stored for years as they are no longer used hence the technology V price so might have a little bump or dent in the fins.

let me know if you want to order one