mahindra 4035 hst

Howdy. Over the weekend, I test drove a Mahindra 4035 HST and Kubota L4240 HST, both with a FEL. There is one dissimilarity that really sticks out; the 4035 weighs 1146 lbs. more than the 4240, though it makes four less HP. I realize that weight can be an advantage in certain applications...

What is the largest tiller that you would run for a 4035 HST tractor? around 33 HP at the PTO. Would love to get a 72" - but seems pushing it alot! Thoughts?