Intl 4900 dump convert to hooklift *need stretch

I have a 4900 dumper I want to convert to a hook lift bc the truck I currently only used in the winter to spread salt n plow. I am going to go with the ampliroll 120 My truck is currently 86"CA need to stretch to 120" CA. For the stretch is it better to add on to the rear of the existing frame only having one weld and remounting the spring hangers or cutting the current frame and adding to the middle having 2 welds. It is a double frame I know to stager the cuts. And I'm aware about the driveshaft work including adding a carrier bearing. I have done a bit of research and think the best way would be less welds but I think the 2 welds would be easier. I read pros n cons of each.



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