It all comes down to money , of course .
I would really consider a 383 stroker or a small block 400 replacement because you probably could bolt that right up to your transmission .
I bought a brand new 1977 Blazer with the small block 400 . I think it was rated 175 ? HP . Black with Rallye Wheels . Sweeet at the time .
My best friend bought an identical Blazer with the 350 .
We were towing ski boats then , like down to Shasta .
That 350 was one sick puppy .
The stroker 400 worked great towing a ski boat in that era .
Now it would be a slug .
Like my Pop's always said " There ain't no substitute for cubic inches " .
He's been gone a while , long before Turbo Diesel pickups .