Roof rack max weight?

Stock 1992 roof rack: How much is that max weight these can hold under trail stress? I want to store atleast 1, 5 gallon gas can maybe two. I was considering having the roof rack mounted on the stock rails with new cross racks. But if the stock cross racks can hold the wight I'll keep them. Anybody have an idea?

Tyler-

Being a former Yakima and Thule salesperson who has flipped through a bunch of catalogs a bunch of times, I beleive the tracks for the roof rack are rated to about 165lb. The factory bars however probably aren't going to hold that kind of weight because they are not very stiff and will bow a lot. I have however strapped plenty of canoes, kayaks, and other things onto factory racks without any problems. If you can come up with a safe and secure way to strap 2 5gal cans to the factory bars, I personally don't see why you would need to replace them or upgrade them. If you want to start carrying those 2 cans, your spare tire, a hi-lift, spare parts, and a kitchen sink then definitely upgrade to a gutter style mount with some after-market cross-bars. That's my $0.02.

I have a Surco rack attached to my OEM crossbars with some stainless u bolts. I have my 31" spare up there and have a large camping box and my shovel up there and have some bowing of the OEM cross bars but in the last 6 months that I have had it up there no problems to report.

Thanks guys, I'm thinking of just removing the stock bars and building new steel bars that tie into the roof so I can put shovels and tents later on if needed.