Will my 454 fit in my 1978 Stepside without much hassle ?

[57NAPCO]

Thinking about doing something (fun?) with my 4X4 Stepside that I bought 3 years ago , it’s just been sitting…

I’m sure it will fit just wondering what I’m up against ? The truck has a SM465 and a 350 in it now. Actually there is nothing wrong with the 350 other that I’d just like to use the big block (that was in my 84 K30) that’s been sitting in the shop.
Thoughts, tips, positive or negative
…..On a side note, what are my options, if any, for something other than the sm465 ?

The customer…