I am wondering if the yz426f radiators are a bolt in on a yz400f. I am told the 426 has slightly bigger radiators than the 400 and I would like the additional cooling. I don't want to have to rebuild the whole bike to do it however. Aftermarket tusk rads are available, but only listed for the 426. If they would work, I think it would be worth a shot. Thanks in advance!