Need help getting truck level

[K10Chase]

Kind of a long-winded question, but I have a 76 K10 that is lifted what is supposed to be 4in from the last owner with 33x12.5r15s. The problem is I do not know the brand lift I have, I know its blocked in the rear and has rancho shocks and rides pretty stiff. The reason for this post, however, is ever since I've owned the truck it has a small rake on it with the front sitting lower than the rear and I am to the point where I want to get it to sit level. I am also considering possibly moving up to a 35x12.5r15 at some point so I am taking that into account when looking at possibilities for lifting the front end more. I'd rather not trim the fenders, so does it make sense to buy a 6" leaf lift for the front and leave the block in the back to make it sit level or should I switch to a shackle flip in the rear and take the block out? I do use the truck for work so I want it to still be practical to carry loads. Like I said this is a long post, but any help is appreciated. I attached how it currently sits below.