best engine for 81 Regal?

[Bubble11Gump]

Whats up my new brothers! I've been a long time looker, just got my screenname-and gbody! wanted a regal since i was 14, 19 now and have had plenty of cars since then. But with all good comes bad, i finally got the car- and it feels like a chained dog. I was told that the engine is from a 92 Sierra, 5.7L, but was told nothing about the trans. the guy said he hasnt even tuned the engine up since he put the engine in!! i have a choice to make, with engines selling waaay under what everyone else has been saying online, i have a plethora of options. Cheapest are as follows #1. LT-1(from 95 Caprice)-150 bucks, #2. 5.3 Vortec (from 2004 Z-71), or the cheapest, my 92 Roadmaster's TBI 350,...FREE?
so whats the easiest to do?

 

[DRIVEN]

Doesn't sound like you've done any diagnostic work yet. Done a compression test? Is it carbed or TBI? What's your gearing and exhaust situation? We need some help here.

 

[Bubble11Gump]

sorry i took so long to respond i can figure out how to change my password, but anyways. i found out last night that i have a transmission fluid leak around the dipstick tube! but when i drove it it was 3 quarts low on oil AND transmission fluid, i guess thats why he only wanted seven hundred bucks.. i also found out the choke was missing on the carb, how do i know? it was in the glovebox. believe me i couldnt make this sh*t up. he turned the timing down, i have no idea why and there was a screw holding the choke plate open.

 

[DRIVEN]

So once you fixed those things does it run better?