Hey there I just ha a fresh rebuild on my 1972 302 and slapped some performance parts in her and its been running like junk after I drove it around 50 miles. Started out with engine running rough so I replaced plugs, wires, and adjusted carbs and also inspected distributor. That did not fix it. I ordered 2 rebuilt carbs 1406 and one 1405 jetted down to 500 setup. I got the carbs in the mail today and went to drive down the street after the car sat for about 2 weeks and it started smoking from under the hood. I pulled over and left the engine running and noticed oil smoke and some leakage on the right rear of the engine. I also noticed what looks like some smoke stains in two small areas on the left side of the intake where they seal to the head. I turned the engine off and it had a small stream of white smoke pouring out. I have been having a hard time with me carbs on my dual setep and have been running to rich. Does any one know what could possibly be the problem? I called a guy and he said it could be bc the heads were not torqued to specs and resulting in seal leakage. I have pictures to post of needed. Hopefully I can get this fixed with my budget and space for work.

 

Who did the rebuild and exactly what was done?
Depending on what was done, what was replaced, and how strictly the better procedures were followed can definitely have an effect on the final outcome.
Are you trying to run dual carbs on this or are you trying different carbs hoping to come up with a different result?

 

It looks to me that who ever built that engine didn't follow one old school rule in torque and that is do it three steps and wait about an hour in between them to let the heads settle so that they'll seal up proper. and remember that not all 302's were boss engines. if you're trying to run duel carbs remember that they are to be set up in stages if they're not it will run like crap and way too rich.

 

Ok, I had it rebuilt by a machine shop named Dons Machine Shop in Monks Corner, SC. I took a closer look an the oil is coming from around the bott of the valve cover... So that was an easy fix I thought... Went ahead and too the valve cover off and torque checke the heads and those checked out good. Replaced the gasket for the valve covers and the problem is still present. It is still smoking and ha that stream of smoke coming from where the head meets the intake. Also I plugged up anything around the carbs that would possibly cause a vacuum leak and it is still revving high at idle but when in gear at around 1k.
While having the rebuild done the engine was bored, new forge pistons, double chan timing system, block checked at machine shop, roller rockers, new JC Enterprize 210cc heads, and of course the plugs and wires which was just installed. Also put in a mild cam. I tried starting it today and the first few start up I had a flame come from my carb and then the motor cut. I'm seriously thinking about having a shop take a look at it bc this is becoming way too mich time spent away from the family. I'm getting the silent treatment from wife haha. These problems didn't start until I put on the 2 rebuke carbs....