Hey guys, first post and all that...
I did a bottom end (main and rod bearings) rebuild and new headgaskets on the 305 in my '79 C10, motor ran fine for about an hour and then started blowing smoke out the Driver side exhaust. I pulled the plugs on that side expecting to find a blown oil ring on one of the pistons but found oil on all the plugs. My current thought is perhaps the head gasket slipped when I was installing the head on that side and there's oil blowing into the bore. There's been no loss of power at all, motor runs just fine but as I said, it's blowing smoke only on the driver's side.
Motor is stock 305 with a 350 intake and a Rebuilt Rochester QJet. Dual 2.5 Exhaust and a stock TH350 trans. (Some torque converter drainback problems but that'll be fixed soon too)
Don't even bother with replying if all you can say is "Get a 350" I've got one sitting on an engine stand that I'm rebuilding but I want to fix the problem with the 305.