i have a 68 gs400,iwant to change the lifters and pushrods over to the1970 and up style.how should i block off the oil ports to the old rockers and should i install a lifter port bypass line?should i keep my old rocker arms shafts? 1968 gs400 1970 442 conv. w-30
I am also very curious about this as I have a car that I'm about to pull out of long term storage, and I plan on having a look at every item on how this car was previously done. My car has the 70 and up pushrod/lifter combination, with 68 rocker arms (68 Block/Heads) . I recently purchased Steven Dove's book and it was very vague when discussing this subject. He regards the 68/69 rocker arms to be the best factory rocker arm. Last week I had a good look at an old rocker arm, and I don't see how this setup is going to get proper lubrication through the pushrod. There is a small very hole coming through off to one side of the rocker, with no groove to distribute the oil evenly. From what I can see, I would think that the 68/69 lifters with 70 up pushrods would be a better solution. Was there problems with the oiling via the heads method? The 68/69 pushrods are a joke, so they should be replaced regardless of the combination. Hopefully one of the knowledgeable people on this board can shed some light on this subject. Thanks, Todd
Basically you need to of course change over to the 70 up lifters with the oil holes in the top and hollow pushrods. You can buy what's called hybrid pushrods that have the larger diameter tip on the rocker side for the 430 style rockers from TA performance, But I personally have never done that, I just use regular 455 style aftermarket pushrods on the 430 rockers. The oil will go up trhough the pushrod and into the hole in the cup of the rocker and from there it will get to the shaft and the tip. I have used this method many times and for many years without a failure. You will want to plug the oil holes in the heads, mostly if you change to the 70 up style of rockers, roller rockers will also seal up the holes. There are a couple of ways to plug the holes in the head, depending on whether the heads are still on the block or not. I f the heads are still on the block, just clean the oil holes on the front rocker pedestals , these are the small aprox 1/8 inch holes right next to the bolt hole for the rocker, on each head with some carb cleaner or brake cleaner, blow the hole out with air to dry it. Mix up a batch of quick set jb weld, don't use the slow set stuff, let the epoxy start to cure, so it's not so liquidy, then just use a small screw driver and push it down into the oil hole. Let the stuff cure up and you will have a blocked oil passage. I recently dynoed an engine using the 430 rockers and 455 style pushrods, this engine was run up through 6500 rpm with no valve train problems whatsoever. Don't misunderstand me here, I am in no way saying the hybrid pushrods are not the way to go, All I'm saying is that I have been doing it the way I do it for over 15 years, long before the hybrids were available and in fact did not even know they were available until a couple of years ago. The engine made peak horsepower at 6200 rpm. The engine was built with 76 casting heads, probably should'nt post any horsepower numbers so as to not start a ruckus on the board! LOL. Jim Burek P.A.E. ENTERPRISES
