This is the procedure to be followed in adjusting L-head valves. The 4 cylinder is the one I present, but the 6 is similar.
The F Head is much easier, but thats one of the reasons why they developed another engine.
Start by removing carburetor linkage, choke and throttle cables and fuel lines . You will want to remove the fuel line from the fuel pump. Cover the fitting with tape or something to prevent debris from entering. Drain and remove lower radiator hose. (I know its extra work, but it will make manifold removal much easier.) You can work with it in place if you wish.
Remove the carburetor. Next the manifold.
Remove exhaust pipe which has one through nut and bolt and one tapped bolt.
Now the fun part….. Your manifold is held on by 5 studs with nuts and 2 machine bolts. Go easy as snapping one off is going to take all the fun from this job. It might help to put some penetrating oil on the surfaces you can reach a few days prior to removal attempt.
Grab yourself a 9/16″ socket wrench with several extension bars. I use both 1/2″ and 3/8″ for its smaller profile. You will also find that a 9/16″ box end ratcheting wrench will make life much easier when you go to remove the 2 underside nuts. Start in any order you wish. Take it slow and if things seem like they are not progressing, you may need to apply heat. Oxy-Acytelene torch is great,(Don’t get too hot) , but standard torch setup is fine, especially if you get some MAPP gas for a hotter flame. For the machine bolts, apply heat to the block…not the bolt. On the studs, you will have to put heat to the nut and stud. This will help break up the rust.
As mentioned, because of clearance issues,the box end ratchet wrench works best for the 2 underside nuts , but a 3/8″ socket used WITH a U joint might also work. My 1/2″ U joint is too large.
Once you have removed all 7 fasteners, pull off the manifold. If it’s stuck,I use a small wooden wedge to break the gasket free.
Again… Not too much force. Cast iron breaks!
Remove 2 long valve cover bolts and cover. You are ready to adjust the tappets which I will discuss in the next writing.
The procedure of explaining is really very easy method thanks