Since both the 350z and altima both have vq35 engines, I was wondering about swapping my 260hp engine out for the '07, 306hp version.

Or I was thinking of just tuning my se-r engine, but is it realistic to get over 300hp(NA) from 260hp without rebuilding the entire engine?

What do you guys think? Would the 306hp engine be compatible with an auto altima se-r? Do you think the auto tranny is built to handle 306hp?

While I would love to have a VQ35HR in my '02 Maxima, there is no way I will put forth the expense nor customization to install a RWD motor into a FWD car. There will probably be clearance issues with the intake manifold as well which would require more expense.

That being said, look into a set of headers for your current VQ35DE. The Maxima CatMan headers are good for 30whp alone (Not sure how good the Altima headers are but they should be equiv). Hi-flow cat and cat-back will add another few hp as will a good intake. UDP or lightened pully will help free some ponies up as well.

For the tranny, look into a valve body mod and install a tranny cooler as well.