Leak down /compression test

I found an engine at a local wrecking yard, it is the LA 360 with roller cam (1990 dodge ram)

The engine has not been pulled yet, and it is available for $450 After it is paid for, they will do the compression test, leak down test, run it, check for smoke, noise, etc. if it passes these tests, it is considered sold as a runner. If it fails tests, it will be sold as a core and the money refunded to the purchaser.

My question is: what is considered to be good / acceptable numbers on these tests? I was told over the phone that the compression should be between 150-170, with all cylendars similar to each other. Z'at sound right?

And how about the leak down test? The guy on the phone was not a tech and didn't know.

Also, I am specifically looking for an 88-91 LA 360, as I have learned right here, on this most awesome site, that this engine will basically bolt in as a replacement for my 318, and it has the roller cam in it.

So that brings up this question: how can I tell by looking at it if it is genuinely the engine I am in search of? Will there be a number cast into the 360 block stating that it is the roller model?

HELP!!

And thanks!