I would replace the timing chain. We have double timing chains, so stretching is minimal, but with 132k miles, AND you're already going to be right there, it only takes 5 minutes to change it out, and they are cheap. But that's just me.

And yes you must replace all the gaskets.

 

I think i will just because its right there. I dont plan on doing many mods to this engine because of the milage. I want to eventually get a 347 long block crate engine when mine dies.

 

update

cover is done

was a pain with a couple fabracations to neg.cable connt. to cover.

not to mention SUMMIT sent me the wrong cover. I even verified over the phone with them and they said it would fit. Because the part # had 289/351 1968-78 on box. they said it will work. Not.... I had to buy another one from Napa auto part locally. It was the exact match to mine, they also ordered ARP bolts for it and only 6 bolts actually worked. I'm not happy with summit right now, oh yeah the gasket for the water pump was the wrong one too. I'm not going to be ordering from them anymore. In the process i cracked the overflow resovior and now i have to buy another one, or find at junk yard. S**t when will it stop. My rad,t-stat, waterpump, timing cover,all hoses have been replaced. I hope that's the end of my coolant leaking adventure.
Here's a pic of the success!!!

 

Here

 

another