General LSX Automobile Discussion - LS Motor Dilemma

So here's the deal I bought a 78 trans am as my new project car, couldn't figure out which direction to go as far as a motor but eventually settled on a ls. Figured if I'm going ls then I'm going all the way and picked up a ls2 out of an 08 TBSS. Finally got my car out of storage and to the new house and what do you know I bought a rusted out piece of crap. So the search was on for another car, well I used to own a 84 coupe deville but my grandfather fell in love with it so i gave it to him. Time went on and grandad passed away at the age of 89 2 years back and the family decided I was the rightful owner of the caddi and gave her back ( after they drove it into the ground ! ) anyway long story short I'm gonna bring her back to her former glory. Here's the dilemma do I put my premium fuel drinking ls2 in her which I only bought because I planned on building a street strip car or do I sell or trade it for a more cruiser friendly 87 octane drinking 5.3 ? I will never in a million years attempt to hot rod the caddi, she's gonna be a low speed Sunday cruiser. Give me your thoughts and why you would go with either choice. Thanks

I cannot imagine putting that much work into that car to be a cruiser. However, making at a totally sneaky sleeper, that would have my interest. In which case, 6.0h boy!

Yea sleeper would b cool but I would have to keep it quiet as possible I hate hearing old Cadillacs with muscle car exhaust. I was thinking a 5.3 for the better fuel economy, I'm gonna take her on some nice long trips frequently. Wasn't concerned about that when I was going the street strip rout