If its a bit smokey, buy it anyway.
Flog the pisser out of it, and if it comes good, bonus. If it doesn't, nip down to the wreckers and grab another engine.
The last 4 out of the 7 AE9* I've bought recently I purchased (very cheaply) specifically because they were smokey... 3 of those 4 just needed a damn good flogging and a big gulp of denatured alcohol down the intake, the other one needed valve stem seals.
The AE93 RV's seem to do it more often.... Must be a 7AFE thing.