That is a 5913 head so that indicates 54-55 head. The more important question is what year is the block. If the block is also 54-55, then the rocker arms should have a groove inside each arm that directly intersects the dribble hole on the arm. The reason this is important is that in 59, GM made its last changes to the oiling system for the 235 and 261 motors. Instead of bleeding pressure from the rear cam bearing to feed the rockers, the rockers in the 59 and up blocks were fed from a direct passage from the main oil galley. This increased the oil pressure and volume to the rockers. At the top of the block, an orifice metered the amount of oil reaching the distribution tube/connector on the rocker arm assembly. On the 59 and up blocks this orifice was larger then on the 58 and earlier blocks to allow a larger volume of the now higher pressure oil supply to reach the rocker arm assembly. To control the oil flow at the rocker, so that oil dribbled out of the rocker arm dribble hole, GM offset the groove in the rocker.
Here is where the issue appears. Lets say you have a 55 block that goes south. A friend gives you a 59 and up block, either regular production or service replacement. If you bolt on the 55 head and rockers, you will get an increased amount of oil to the rockers that is not metered correctly and can flood the valve stems so to speak. GM supplied a plug and a special drilled head bolt that was used for these situations so that the oil could be redirected and metered in order to use the later block with the earlier valve train.
On the photos, it looks like you have a lot of soot and some oil there on your finger. Looking at the gasket, it does not look like you have a very good seal, especially on the headers. This is not exactly uncommon with the Clifford headers. It also looks like you have some wetness in the intake ports. So just as an initial issue, I think you want to consider using a Rimflex gasket instead of the Clifford gasket or stock gaskets. It is imperative that you have a good seal.
I might also retorque the head just to eliminate any loose bolt issues.
So maybe start with finding the casting date and part number on the block, retorque the head and get a Rimflex gasket installed.
Finally, what weber carb are you using? The non-progressive 38/38 or the progressive 32/36? The reason I ask is that I ran a pair of 38/38 webers on my Clifford intake and truth be told I tried my best to get them to run right. They always ran rich, started up rich and with a big cloud of white smoke, had a stumble on hard acceleration, and no matter what I did in terms of jetting or adjusting I could not get them to run right. Jetting was expensive and a pain, and I struggled with weber tuning, or maybe it was just not to be, I dont know. A couple of years ago, I switched over to a pair of Holley 350 cfm two bbl carbs and that solved the issue. You may want to consider that alternative.
Last edited by Dragsix; 10/05/2023 1:50 PM.
