440 source ductile adjustable rocker arms.

A bit more on cast rockers.

Jig up a couple of old 273 rockers and measure the lifts
if you have time.

Even the Mopar Perf. Iron Small Block rocker often varied .010 to .020 at 450 lift.

Back then one of my sponsors let me go thru his whole stock of MP rockers
to find 16 within .010 varience out of all of them. Then they went off to Rocker Arm Engineering
in No. Calif. to have ratio corrected/ geometry rscorrected/offset bushed to get to 1.5 ratio within
.001. between them all. With his shafts and hardware about a $750.00 deal ( a lot in the 1990s)

Only the Isky Big Blocks every checked correctly = Not the Sig Erson or Mopar ever real close to 1.5.

Finally about 10 years ago, NHRA in its wisdom let us run Roller Rockers. Not any help for Mopars but a
boom for GM with their stamped stud Junk. Even the expensive Roller Rockers, I would not trust in a street car
that you expect to run for years and many miles trouble free.

We put T and D and the top of the line Harlan Sharps (Both a Fortune) on our Big Block Stockers and did not
find ANYTHING over the Isky Iron Rockers = Period not a Hundred we could find!

If we had run out of the box Small block Cast Rockers with their random observed variance on our stockers = We
would probably not have 1/2 of our 40+ NHRA National Event Wallys on our shop shelves.

Just my .02 worth = For Free!

As you have probably guessed, we have spent well over $1,000,000++ in the last 50 years on racing Stock and
Superstock! AND I would do it again without Hesitation.