273 adjustable rocker arms

What ir3333 wants, ir3333 gets LOL.

Here is rocker ratio data for 1 stamped rocker. This one came off of a 340 or 360.... so the rocker and the shaft are just a random sampling. The results were surprising.... I have seen numbers reported at and below 1.45.

Same test set up used on a 675 head as shown above with the change of the rocker, shaft and pushrod.

Valve lift/ ratio (excluding lifter-to-pushrod angle)
0.049/1.41
0.101/1.58
0.148/1.54
0.199/1.53
0.253/1.53
0.312/1.54
0.375/1.54
0.442/1.56
0.496/1.55

Again, toss out the 2 lowest lift numbers and average the rest and you get 1.54. This is without the loss of lift due to the pushrod-to-lifter angle. If you factor in that approximate number, the result is an overall lifter-to-valve ratio of 1.49-1.50.

Not bad at all....