Yes.
If the cubic inch is the same the motors should swap out ok. You will have to change some parts but most Chevy motors will swap.
YES, That would be a direct bolt in with NO problems. EVEN SWAP
Swap the relay with another like relay.
You can if the year of the 454 is between the years of 1988 to 1995
yes you can swap the 454 for the 350 its compatible usually any Chevy engine will match in the same vehicle might have to do sum fabrication but in ur situation you should be fine
change ecm also
As long as the 350 is a fuel injected engine / TBI / Throttle Body Injection engine there is NO difference.
Yes But they have different plug ins on the throttle body so you will have to you will have to swap the throttle body also
NO.
Try craigs list * www.craigslist.org
1964 to 1987 El Caminos swap to their A-Body sister cars and vice versa
Yes you can.