Hi guys,

I have just received a pair of heads from a very kind Y Blocksforever forum member and fellow Y Blocker Jumpstart (Bob) bloody legend!

Anyhow, I’m trying to figure out what ratio rockers are on the heads, I believe one set is the 1.54 due to the ECG6564B2 stamping and the other set is an aftermarket replacement 1.43 (no stamp) according to John M’s website.

After searching around the posts, I found the 1/4 and 5/16 inch drill bit method that Ted suggested and gave that a go. The aftermarket rockers fits the 1/4 inch bit loosely but the 5/16 won’t fit.

I also tried the method Unibodguy suggested which was measuring the length of the rocker, apparently the 1.54’s are 3 inch and 1.43’s are 1/4 inch shorter

Not too sure though, so I though I’d throw up some pics and see if you guys have any ideas?

ECG6564B2


1/4 inch drill bit test (bit tight- doesn’t exactly fit)




Aftermarket rockers



1/4 inch drill bit test (fits loosely)




Also one last question-
Does it matter if the rocker area that contacts the valve spring (unsure of the technical name) is slightly off center to the spring?



Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.

From the photos, some or all appear to be 1957- (58?)  1.54:1 ratio, marked B2, as they came with the one piece adjusters. So, all or most factory1956- 1:54s are marked B 1 & have 2 piece adjusters, according to a recent article in Y-Block magazine.. Two pce adjusters also applies to 1.43:1 rockers.   Note; that the one pce adjusters have an interference thread so will not interchange with the 2 pce adjusters. Also, there have been some reports of the one piece adjusters not holding their set, in long term service, so keep that in mind if some of your valve sets don't hold. Thread locker might work in that case. The issue of the rocker not centering is not usually a problem, but U could buy large thin washers for the shafts & shim them slightly if it bothers you. 


Paul

Some of the rockers will be off center in relation to the valve stem.  That is normal.

If the aftermarket rockers are not manufactured exactly to the stock specs, then these methods will not work.  That could be what is happening.


Lawrenceville, GA

Dennis 22:  What ratio are you looking for. When I built my 312. I had a set of rocker arms made  That way you can have the ratio you want. I live close to  rocker  arm specialties, in Anderson  California. And worked great for me.  This is something you might think of. Just a thought.  Bob