The Ford Barn - View Single Post - Questions regarding idle on early Y-block

TedEaton · 07-21-2015, 07:14 AM

Based on the pictures of the fuel bowl cover, the carburetor is a 1956 model. Based on the tag number, it's a 1956 Ford/Mercury 292 carb and not a Thunderbird carb. Check out the List number stamped on the back flange of the carb and see if it is '1162'. If it is, then the tag number is correct.

At this point it would be helpful to know the casting numbers on the heads. The 239 heads did have the smaller ports and as such, there is the potential for vacuum leaks at the intake port with the later model manifolds. Are your spark plugs 14mm or 18mm. That would be another clue as to whether the heads are from a 239 or 256 engine.

07-21-2015, 07:14 AM	#25
TedEaton Senior Member Join Date: Nov 2012 Location: Central Texas Posts: 155	Re: Questions regarding idle on early Y-block Based on the pictures of the fuel bowl cover, the carburetor is a 1956 model. Based on the tag number, it's a 1956 Ford/Mercury 292 carb and not a Thunderbird carb. Check out the List number stamped on the back flange of the carb and see if it is '1162'. If it is, then the tag number is correct. At this point it would be helpful to know the casting numbers on the heads. The 239 heads did have the smaller ports and as such, there is the potential for vacuum leaks at the intake port with the later model manifolds. Are your spark plugs 14mm or 18mm. That would be another clue as to whether the heads are from a 239 or 256 engine.