I worked in a Chevrolet dealership parts department back in 1963, and as best I can remember the 735 cam was the over the counter cam that was specified in the parts book and it had a 736 casting, Someone smarter than me can fill in the blanks here, but I believe the actual cam profile for the 736 Eonic cam was different than the 735. In addition, the Eonic I have has a casting for the shaft of 046 and the 736 is machined into the end as you can see in the photo. I might have a 735 around here and will look to see what casting it has. The Chevrolet book I believe calls for a 736 casting. If that is actual(some one go look at their 735 cam) then they are definitely 2 different castings, but might have the same profile. My memory is a little clouded by time by the fact that the older I get the faster I was, but I think I remember the over the counter cam was the 64-65 Hperformance cam that was the same HP rating of 425(of course we all know that was suspect). Anyway, I believe in 1962 Chevrolet had the local Detroit cam company Eonic grind the cam for the Z-11 for them just for the 427 engine. I never did believe it was the same, but never took the time to check the 2. Since I had a 409 with a Z-11 top half in a 61 back then, I thought that cam was entirely too mild anyway, so I opted for a Crane Zip 606, .606 lift and a 324 duration and after quite a few runs lots of bad things began to happen. The cam Phil has did in fact come out of Dick Harrells car because a friend of mine owned it at the time and he was the one that lost the lobe that is bad on it now. I sold it to Doug Hughes way back and was surprised that he still had it. Never thought there were not many of these around, but guess not. I do not plan on selling this one, I will probably put it in an engine I am working on, thanks any way. If I find the other 735 cam I will see what I find and will post the results, thanks, Pat.