John,
I've checked this with four different dealers over the phone, including Carver. Three of them had hesitation because the information is apparently laid out with foonotes and asterisks in their sales materials. As I recall, there was interference with the front tires. I really cant say I understand this, because the front R4's dont look particularly bigger than the turfs. So, I would advise anyone to have their dealer doublecheck. Maybe there's an asterisk on one of the asterisks. There's not a lot of firsthand knowledge on this subject, I suspect, because I dont think a lot of Grand L's are sold with belly mowers.