TC Generator swap

My generac impact 36lp had given up with only 220 hours, most were for exercising. I've been using a portable if needed. I recently got a 2500 onan thats and early model than the current 2500i. When I swap generators should I try and run power through the generac inverter, since the 2500 i have is not an inverter generator or just just run the power leads to the transfer switch...

Thanks Dan.