[mr48chev]

Yep they need to be welded up and you probably need to figure out if you have all the needed fender braces on the truck. One of the problems we tend to run into on these is that guys who worked on them years ago often didn't put the braces back on the fenders where they are dearly needed. They end up cracking from just the movement of the front end. A lot of guys who swap V8's into them leave the two firewall to fender braces and that is the cause of a lot of squeaks and rattles. Also when guys swap later engine and trans in and cut out the crossmember under the bellhousing it weakens the frame and lets the cab settle the brackets on the frame that the cab mounts on. this in turn puts stress on that area of the fenders. If you look close at a lot of trucks that have been running V8's and automatics for a number of years they will often look just a bit bent in the middle between the cowl and the nose and that is the reason why.