Loud(for an svx) clacking upon startup?

Ok recently the svx has gone back on the road..its been about 5months, needed bearings and some TLC. Last night i cranked her over to move it across the street and noticed a clacking noise that went away after she warmed up, bieng a Z28 owner i thought to myself !!damnit!! lifters but after it went away the only thing i could think of was piston slap.....aluminum blocks tend to do that (LS1 vette's had a TSB about this). IF its piston slap then its not a problem givin the age of the car, 1994. A bad lifter is a problem and can cause worse problems down the road. Any other possibilities?? This car needs to run since my Z28 is getting Cam, heads P&P done....i need it for winter


Thanks guys