Help 351C guys - Carb

[Explorer]

Remember I said this wasn't a solution. More of a fine tuning thing. After everything else is right you still need the airflow in. Standard paper filters flow 5cfm per square inch, Hi-Flow like K&N flow 6cfm per sq. in. There is another formula for calculating filter area size needed and all these are figured at peak rpm.

 

[bax]

Check for the number 4 in the front and rear corners on top of the head.

 

[Explorer]

FYI: This is what I put on mine. 600cfm Holley w/1" plate between carb and intake. Max filter area for the space available. It fits, just barely, K&N E-3740 14x2.3 something and 66-1401 filter top. Your 351 may sit a little higher. Definately made an improvement.

 

[GrillMaster]

do I have to take the valve covers off or are they on ther front and back vertical face?

 

[bax]

No you don't have to take the valve covers off. No they are not on the vertical face. Front or back top corners of the head. The valve covers do not cover the corners of the head.
Extending the vents: Bowl vents are those 2 tubes sticking up on the top side of the carb. If the carb gets bounced around gas will spill out of the vents= flooding on inclines. If you extend the vents it makes it harder for gas to spill out. Common way to do this is to install a piece of tubing from one vent to the other, Then make a few holes in the tubing on the top side so the vents can still vent. Holly also makes baffles that go inside the bowl to help stop this problem.

 

[Madgyver]

Here is a pic of the #4 on the upper corners of the heads, This is a 351C with 4V heads.. It will also be a 2 or have no number at all, most times it will be a 2V head if it has no number.

Also a pic of the 650 Holley DP I used to break in the cam....

 

[broncnaz]

See my Holley carb tips tech article to left. It works on DP carbs equally as well. Your back fire through the carb is probably due to to much ignition timing or just to much fuel upon startup

I agree this is more of a tuning problem but a smaller carb will help driveability and are easier to tune. Big carbs tend to need to be setup richer than normal to balance out the mixture due to more airflow.

 

[kirkallen143]

Why don't you give us a pic of your plugs. We can tell you if you are rich or lean, too much timing or too little and if your heat range is right.

Kirk