I have used the truck timing set for close to 40 years now. I was looking at the copybook that I keep my notes on the 235/261 motor builds I have done over the years (yes old black marble, first entry for motor No. 1 is August 1979, there are 47 motors after that) and I used the truck set on all of them. About a third were restorations, the remainder were modified motors. Some have said they are noisier, I have not heard much difference between the two. The fiber gear was the predominate gear used in these motors from the factory but after a lot of use they could and did self destruct usually resulting in a few bent intake valves and other assorted carnage. The truck set is just a more durable part, 2516S is the common aftermarket part number that a number of manufactures use. They run in the $50-70 range new although I have paid less on ebay for RNOS sets in dirty boxes. As for installing the cam gear with the cam in place, as Jerry said, it can be done. Me, I am a big chicken, so I have always pulled the cam out of the motor to install the cam gear. A couple of the gears I have had over the years have been somewhat tight even after heating them up. I don't know that I could have gotten those gears on with the cam still in the motor so use your best judgment. The aluminum cam gear is not one you can remove and reinstall and maintain the necessary sort of interference fit.
