I towed a 16 foot dual console Starcraft with our Sienna for a year. The whole package comes in around the same weight as yours. We have the big V6 in the van, and it is rated for the same as yours. Never had any issues on the ramps, never over heated and tranny is still solid - even Burwell where a lot of front wheel vehicles spin out. Our Sienna came equipped with a tranny cooler (I checked before I started pulling it), BUT, the van rides so low to the ground that even without a load in the back, with the boat on your clearance is a real issue. So you need to get a tongue with a big vertical raise on it and drive slow on a lot or roads. On more than one occasion when accessing a lake, I bottomed out - did it once on the Restoule access road, only going 60 in an 80 zone. I thought about adding air shocks to the van, but in the end just decided to buy a truck as my old SUV was in need of replacement. Now the Mrs has her taxi for running around when I'm on the water.