Hi JSR some important points:

since your model is a '76 then it uses Hex bolts for the cylinder head and that means 3 things:

-You don't need new bolts because they are not stretch bolts.
-You will have to re-tighten your cylinder head after 300-600 miles.
-You engine can't use stretch bolts(according to the manual)

sources:
https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/615/05-105.pdf

https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/615/05-110.pdf


Sugar Bear already mentioned most of the important stuff.

You can check the stretch of your chain by pulling on it to see how tight it is on the sprocket or by the 2mm method in the manual:

also push on the tensioner rail to see how tight your tensioner is.


Because you have the vacuum pump off I recommend checking the end play of your timing device (Should be 0.05-0.12mm) If it's excessive then that can cause your vacuum pump to fail.