I had my '36 engine rebuilt several years ago, but only finished the car recently. This week I replaced the Cam gear, as the distributor shaft froze, stopping the cam, and the fiber gear was ruined by the crank gear causing the engine to fail.

While I was removing the pushrods, I noticed that they came out freely when I removed the rocker arm assembly.  I took off the side panel and found that there  was no valve guide assembly.  I opened the side panel of an old engine I bought, and found the assembly in place.  I drove the rebuilt engine several miles before it failed?!!!

My question,  did the absence of the lower valve springs and guides contribute to the failure? ( I don't think so), and, since the car ran well. are these guides and springs necessary for the engine to run properly, or are they commonly removed by rebuilders?