What engine
The 25 can be trailered and there is no issue with the beam. The real questions are what you are you hauling it on ( does trailer have brakes?)and the towing capacity of the Blazer. Is it a full size Blazer with a big V-8? Does it have a towing package (oversize radiator and transmission cooler). You need to figure on a towing weight of about 6500 lbs. with trailer, boat , motor and gear. Check out your Blazers specs with GM. You might have to add a transmission cooler and watch the radiator.