One easy way to tell high ratio from low ratio is if you look at the oil hole channel with the rocker upside down, you will notice the casting of the channel on high ratio is about 1/8" long and on the low ratio it is about 1/4" long. I have pictures describing this somewhere but can't find them at the moment.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Thank You TERO.    G.S.

56 VIC  Gene Stoehr Sr.

Part # EAA-6564-B shows in my partsbook that it is for 55/56 223 6 cylinder engine. No ratio mentioned there.


Tero from Nurmijarvi, Finland

56 Country Sedan, 61 F-100, 61 F-600, 55 F-620, 52 Mercury

http://www.dlc.fi/~teros

http://www.y-block.info

http://www.hollowheads.net

http://www.fordnationals.net

Since I am still not sure of the ratio, I will ask the forum this; Are ECG and EAA the same 1.54 ratio?

56 VIC  Gene Stoehr Sr.

Those are 1.54:1. Check John Mummert's site for more info. http://www.ford-y-block.com/rockerarm.htm

58 Ford Custom 300 - San Pedro, CA (So-Cal)

Bringing this post back to see if someone out there can help identify the ratio of this rocker arm? Thanks G.S.

56 VIC  Gene Stoehr Sr.

I have several rocker arms Part #EAA 6564-B. What ratio are they? Thanks G.S.

56 VIC  Gene Stoehr Sr.