jeffro22

Working on my 67 289 and need to get a set of rocker arms. These are with the stock heads. What size is the stud and what ratio do I need. Any suggestions on a set of rocker arms.

The lifters are new but are a little dirty from sitting in the car for the past 3 years. How can I clean these?

Also, When I was taking my old rockers off I couldn't get 4 of the rockers off. I got the nut off but the piece under the nut won't slide off the stud. Any ideas?

bwkelley76

...not sure what to do with the fulcrom (the piece that wont come off the stud) Just don't force anything and ruin your threads on your studs or accidentally yank them out of the head! Cleaning the lifters and such you're going to have to remove your intake manifold if you want to clean them manually. Use Marvel Mystery Oil, let them soak in it for a week or more. Otherwise just replace them since they are cheap. Depends on how dirty they are. Do the pushrods also, and blow and look through them to make sure they are not plugged up.

**Whatever you do make sure you put the pushrods and lifters all back EXACTLY where they were if you reuse them. The camshaft and the lifters are mated during the initial break-in of the motor and more as time goes on, and have very specific wear patterns. If you mismatch them they will most likely wear prematurely and cause serious problems.

One thing you want to check for is that the rocker studs aren't pulled out of the head as they are only pressed in, (weak and prone to slipping out) check to see that the are all the same height. One or more that sit higher than the others indicates slippage. This stud-pulling can cause problems and they were know for doing this after high mileage and/or when a large camshaft or heavy valve spring was used. Also check the threads and make sure they haven't stripped, especially if you're having problems with dirty or stuck valvetrain components. Use NEW rocker stud bolts ALWAYS, and if they feel the slightest bit like the threads are loose/worn then double-nut those suckers after you adjust the valves properly!

As far as the rockers you need a ratio of 1.6:1 for. Personally I like the Crane Cams Roller-Tip rockers. They are a stamped steel design just like the factory but they have a little roller on the end that contacts the valve stem. Reduced friction, quiet operation, and a little more HP and better revving capabilities. Also note if they are "rail-type" (self guiding) or not. The rail type have a little shoulder that goes around each side that wraps around the valve stem. You will most likely require the rail type unless you have the heads that have the square push-rod holes for pushrod guiding.

The best bet is screw-in studs and guide-plates but you have to remove the heads and have them machined for those. There is plenty of info out there on everything I just told you. I hope I was able to plant the seed and point you in the right direction. Enjoy and good luck.

Hope this helps.

jeffro22

Thank You for the detailed write up.

The car's motor was rebuilt about 4-5 years ago but was never put all the way back together. It was sitting with the intake off for a couple of years before I bought it. I am trying to see what it will take to get this motor running. I already pulled all the lifters and they look new with the exception of some dirt in the top of the lifter. I am wondering if i clean them or should I just replace them.

I will see about getting the other rockers off.

Can I go with a normal 1.6 roller rocker for a SBF or is there something different about the older 289's? Also, what stud size do I need?

jeffro22

bmp ttt

rmodel65

soft tap the rockers with a rubber mallet to knock the ball loose that keeping the rockers in place(reinstall the nuts so the rocker dont fly across the room

jeffro22

well the rockers are loose, its just when I try to get them off the stud the fulcrum wont come past the threads, almost like it is getting stuck. It's rainy and windy today so I might get soem shop time in and see if I cant get this figured out.

bwkelley76

Your studs if stock should be 5/16 but you may want to verify. I think some 289's could have had 3/8" but rare. Any sbf 1.6 rockers will work if they are the right size for your studs.

As far as the lifters it's your call but if they were exposed to the weather or have sandy dirt in them just replace them with new.

jeffro22

I am wondering since I already have the top of the motor apart if I should look at getting a better set of heads and swapping them out. Would a set of newer GT-40 be good to use on this motor?

also, i haven't been able to find any rockers that are 5/16" , everything is either 3/8 or 7/16 or pedestal mount. Or course if I switch heads then I will wait and get what goes with the new heads

Are my current stock heads of any value if I try to sell them?

jeffro22

Anyone?

my77stang

289/302/351's that had rocker studs were a 3/8 stud and a 5/16 thread on top, they arent really adjustable like you would need them to be, so you'd have to get 3/8 arp rocker studs and guideplates installed from your local machine shop.

yes, GT40's would be a great upgrade, just make sure they mill the heads down a little otherwise you will be loosing your *** in the compression dept.

then, you can either buy pedestal style roller rockers or a screw-in stud conversion kit that can be installed without the need of a trip to the machine shop.

*edit* oh yeah, if you use the 289 heads your gonna need hardened ex seats installed from your local machine shop, otherwise you will not be able to run unleaded gas properly. with the costs of machine work, your better off getting the gt40's and having them redone.