auto to manual swap

I mean manual transmission to a automatic transmission

I've been lookn at a lq4 and a 4l80 out of 02 hd silverado and was wondering if i would be better off swapping out my 4.8l 5speed for this setup. how hard would it be change my truck from a manual trans to a automatic??? just wondering what kind of input you guys would have on this. because i know for a fact the junky 5speeds that come in these trucks can't hold up to a lq4, they barely hold up to my 4.8L. So give some feed back on what kind of nightmare i might be getting myself into. thanks in advance

Shouldn't be too hard. Get the full harness from the donor truck and switch it all out. I'm not sure on the driveshaft if they have the same output yoke or not. You'll need a floor shifter or buy the shifter mechanism from an auto truck and cable. I like the floor shifter myself :cool: Everything else should just swap over except maybe the trans crossmember, get that with the engine/trans if you can unless you know the 5speed unit will work.