I did a quick search and came up empty handed. What type of oil and weight do people prefer running in their y blocks?
You need the extra ZDDP for an older engine you can pay more for the fancy stuff or just use this: http://www.quakerstate.com/en_us/pr...High_Mileage_10W-40_Motor_Oil_(en-US)_TDS.pdf About $16 for a 5 Qt jug at Walmart.
I use the Quaker State Jeff mentioned or Valvoline VR1. The only problem with the Valvoline is it doesn't have the detergent package "normal" oils have so you need to change it more often. I used to use Rotella but I worry about the detergent package being too harsh for a gas engine over time.
The Rotella that many knew and loved is no longer, to meet the newer diesel clean emission standards the ZDDP is a lot less than the previous blends and the higher detergentcy can actually harm an older engine,unless you can find some from five years ago best to avoid it.
My local speed shop carries a Kendall product and at $6 a quart, that's not bad. I've used the VR1 to break in my engine and currently have Brad Penn in it. I'll be changing to the Kendall 20w-50 for the summer.
I know a lot of guys out there buy parts and think "I can do this" and never read the instructions,are you guilty ? Well folks it's the same thing regarding oil selection this is a good guide to picking your oil and how to read the label codes so you know first hand what is in it :https://www.hemmings.com/blog/2012/10/18/tech-101-zinc-in-oil-and-its-effects-on-older-engines/
There was a huge writeup on Speed Talk a few years ago. One of the best oils was Chevron Custom Supreme for wear/price/etc. I use it in my Flathead powered 32 & the Y Block in a 5-30 weight. So far so good Jim