I have an '84 with a carburated 305 that was rebuilt about 5000 miles ago. Prior to the rebuild, the car would have a tough time idling for the first minute or two during inital start up. The motor was rebuilt with new internals (new cam minus valves and push rods, rockers etc however I did put in new valve seals) The block was magnafluxed as well.
*all emissions were removed as well.

After the rebuild the car ran excellent however after about 3000 miles the rough idle started to make an appearance again. I checked and the coolant was low and the car does not leak... ie somehow it is getting into one or more cylinders. Obviously

 

is oil getting into the oil??? or into a cyl?? maybe a intake leak, had a 305 carb leak from the intake alot,

you still running factory carb or aftermarket carb, if so what brand

 

If it's getting into the cylinders, it should be burning it off and blowing it out the exhaust. Do you see white smoke coming out of the exhaust?

 

yeah, there is deffinately white smoke while its running rough. I am really just trying to track down how the coolant is getting into the cylinder(s).
The intake and carb and everything is all stock.

 

sorry, I did not see the comment earlier. I do not believe there is coolant getting into the oil. for as much as the coolant has dropped, the oil level has not changed.