Now 8620 is Pretty Hard Stuff . and those Radii are Critical , so I did a little More Investigation Work - as that is pretty much I did for the second 20 Yrs.
I had Heard of Reports that some Had Experienced - Push Rod Failure !
Push Rod Galling Etc. - being - Chewed Up .. more or Less .
After getting several Sets form Different Manufactures and Different Price Ranges , I Mean Stainless Steel Crower - Full Roller - Lighter then Alu. $569.00
OK so a Comparison of what's Going On is in Order ..
I Never had Gotten 3 Pages of Paper on what to NOT Do - Before - Nor was I Ever
Steered - so - Hard to use Their Push Rods ..
Looking at the Above - Starting to see Why ! ( all the Paper Work )
OK
I Took 2 pc's 1 from S1 & 1 from S2 - which Groupings came in 14 & 2 so Totally
Random Mix from Factory - Not 8 & 8 ?_?
I then Clean & Spun 1 Stock 1972-78 Push Rod in the Rocker Push Rod Cup
Spun @ 1400 RPM's for 1 Full Min. with Oil .. 30-40 lbs of Down Force
Push Rod - did get Rough . . and I didn't like what I was Seeing !
The Design of the Inner Radii is too Sharp and to Small for Stock Push Rods - making for a Sharper Leading Edge - then what should be there .
A Larger Ball Tip like 3/8 = .375 would be Better Choice ..
This Reminds Me of the Oil Filter Canister - that only Fits 1 Motor and Cost $19.95
Type Deal .. Most of Comp Cams Push Rods are Actually .3125 Dia.
My Stock Push Rods in this Motor were .324 Dia. Like a Lot of Older Stuff ..
Didn't Fit in the Bottom & didn't Fit in the Full Top Radii - which only Comp's .375 Does ..
Here what I did :
First I Cleaned them ans Sorted After Inspection : Prepared to
Burnish A Radii of My Own
I Burnished or Cut Polished this with 380 Grit Diamond Dust .
Second Cleaning : Now .010 Break Lead for the Ball End to Ride - Could have even gone more .
See How these Do in 6 Months .. seeing the Block was Sq. Decked .015 & Heads Milled .007 = .022 Smaller ..
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Comp Your SOOooo_ BUSTED !