[arkracing]

I don't know what type of quality job your are looking for - but to do it and have it very nice - i would suggest taking the floor apart -

remove the rear cross sill and all the cross sills (by drilling out the spot welds) - then cut the two ends to the length that you need and re-install the cross sills for a shortbed.

if you try to weld al the way across the bed floor by just cutting and shortening it is going to look bad - unless you are a really good body man - and can sling mud well. the problem with that is that now you have bondo that will chip of the first time you put something in it.

I suppose you could also "Rhino Line" or "Line-X" the bed to hid the welds - but that cost $$$