Fixed up your title..
The conversion will use different ends, and probably need a different length than the stock drums.
The Camaro calipers should take the same ends and length as a 74 nova with disc brakes, as long as the calipers are from the same era. You could call your parts store and ask them if the same brake lines will work for the Camaro as will work for the Nova...
That would be a start. If they are visibly totally different, you may need to get a length and go with a set of universal braided stainless lines.
Which conversion did you buy, is it from one of the aftermarket places like classic industries? Those kinds of places can usually recommend the right line for their kit.
Looking back in my brake hose data I show a couple of lines that have a 3/8 inf end for the frame, and a banjo style fitting for the calipers. A 69 Camaro line, Raybestos # 45-36672 is 16" long, and a Raybestos # 45-38103 is basically the same line but 19 1/4" long...my classic performance catalog shows the same brake line part number for the 69 camaro as they do for the 74 nova, and it is 16" long...