FWIW square tubing is less prone to flex and distortion under load, but in terms of a front cross member, as long as the tube is heavy enough to support the load it shouldn't make a difference
Pop rivits will work, or if you have access to an autobody stud welder, there are replacement pins
http://autobodystore.net/Merchant2/graphics/00000001/uni1003.jpg
Hi All
Found this site a week or so ago....been lurking and reading since then figured it was time to say hello.."Hello"
Been a bodyman for more years than I care to remember...love working on the older tin :)......current projects are a '49 F-1 and a '29ish rpu but they both tend to get put on...