Where can I find the octane ratings for each version of our cars?

 

As far as I know, all were designed to run on standard 87 octane. I don't think Uncle Sam allowed anyone to sell any cars not capable of running 87 regular until late 1990's or later.

 

Factory spec is really irrelevant anyway. For several reasons.
Older engines get carbon deposits, which increase the octane requirement. Timing chains stretch, which reduces the requirement. High elevation reduces the requirement, and so does cold weather. Manual trans cars that are lugged need more octane. Performance chips require more octane.
You just do a good tune up, go for a drive, and if you have issues, pour in a bottle of booster until your next fill-up, when you choose more octane. Repeat as necessary.
If you went and built an 11.5:1 L98, you're never gonna find enough octane, you'll have to severely retard the timing.

 

I was mainly concerned with the fuel injected tbi and tpi models, the only model I know that used 91-92 american octane so far are high output 190hp 305 and the top 350 models.

So did the tpi take 87 or 91 octane?



But some say 9.3:1 and 9.5:1 compression was borderline for these engines.

 

I always ran 87 in my TBI car with no issues at all. Even my wife's 1997 LT1 is rated for 87. They may run better with a higher octane, but like I said govt mandated that every US sold car was to be able to run fine on 87 until late in the 1990's or early 2000's.