if she has bin sittin' a while...like months an' months at some salvage yard...I would do a few things.
a little oil or diesel down each hole, then a few minutes of crankin' her over by hand. Sometimes the rings can seize a bit. It also doesn't hurt to give the cams and other "high wear" areas a little taste of oil before flashin' her up...sorta like you'd do if it was a fresh rebuild. An oil an' filter change for sure. There may be condensation.
Full tune up as Nitro suggested. (after she's up an' runnin',you could foul the plugs,etc, plus, why spend money on an' unproven motor.)
Coolant flush.
Then a compression test. To see if this is the motor "THEY SAID IT WAS".
No mods or add-ons for a while... till yer sure the new power plant is funtioning correctly... if you start messin' with shid an' it doesn't run right . you could end up chasin' yer tail for a while.
shid like that.... RSD.