I would imagine that the front springs are going to get even worse from the extra weight you just added. I don't think Marlin builds a spring pack for that you may want to seek a spring builder to fix that issue. My brother had his 4Runner's springs redone by a custom spring builder and they wanted to know front axle, rear axle, total, the actual spring lengths and some other variables to build him a custom set. Worked awsome they were very flexy and the didn't sag out.
