Just my thoughts on this one:
If the trans was ok before...leave it....just make sure its serviced and has no leaks from seals etc...
Engine: Daily driver....why not consider a roller cam Vortec engine as the base....yes it will need a different manifold....but you will never flatten a cam lobe ever again...
Make sure the heads are not cracked....and run a ring and bearing kit thru it...
You will, in most cases, need to add an electric fuel pump as most Vortecs do not have the fuel pump hole drilled in the block..
You could always go to Scoggin Dickey and grab a new L31 $1999 free shipping...
https://sdparts.com//i-24111530-gm-e...CABEgL-l_D_BwE
That cam you mentioned...way too much for a street daily driver...IMO