Well for me. It's not hard to find . I bet I could find 15 in a few weeks. I recently rebuilt a 1927 white truck engine. They only made 70,000 of that series. Last made in 1930. They made that many ho52 4.10 per month from 69-72. It took me a month to find the roller lifters nos. Yes. Roller lifters on a 27 engine. Last made as replacement parts in 1941. So it's all relative. For me nothing post war gm is rare.
