1979 d50 good deal or not?

so I bought a 79 d 50 with the 4 spd an 2.0 5gb (i think thats the motor code) any way, it is really straight all original totally stock except for the skull shift and door lock nobs. doesnt run too bad but could be better, i.e i'm having trouble with the carb (big surprise huh?) it idle really rough and will emit a blue cloud upon firing then smooths out then surges a little before messin with the carb it would bog down under load like it was flooding out then buck like a bull tilll i let off. I love this truck but want it run like it should can anyone help? i paid waaaayyyy too much for it i know being completely stock and unmolested plus straight. $500 seemed a little steep doesn't it <img src="{SMILIES_PATH}/icon_lol.gif" alt=":lol:" title="Laughing" /><!-- s:lol: -->

i got my 88 for 400. get a weber carb and it will run much better. isnt blue smoke something bad? like antifreeze or oil? i think oil is white smoke? could be wrong.

Blue smoke is oil, either valve seals or rings. White smoke is coolamt like from a blown headgasket.

$500 is a real good price i.m.o.