Factory rocker defeated by pushrod.

-
A91B1079-B161-45AE-95A0-23E5F7D6094D.jpeg

Happened to me two weeks ago on my daily driver Chevy truck. It’s not just spring pressure that causes it, wear also plays a big part. These have over 500k miles on them and this occurrence caused me to check the rest of them. I had 6 more that were very thin at the pushrod cup.
 
I've only had the engine for about 6 months. No telling how the previous owner drove it. No one carries rockers in my state. Summit wants @ $20 to Ship 1 rocker. I'm going to post a wanted ad for the parts needed. Looking into the future I want to run adjustable rockers with a solid cam. For now I just want to get it running. Thanks everyone for the suggestions and help.

mancini sells a set of adjustable made by Harland Sharp rocker kit for under 500 bucks, slick units, and they carry the HS lifetime warranty. Something to consider, and will work well with a stout 600+ lift solid lifter cam, for possible down the road upgrades. Know several people running them with excellent results
 
mancini sells a set of adjustable made by Harland Sharp rocker kit for under 500 bucks, slick units, and they carry the HS lifetime warranty. Something to consider, and will work well with a stout 600+ lift solid lifter cam, for possible down the road upgrades. Know several people running them with excellent results
I cant find them. Can you give us a link? I know they used to offer that deal. I just cant find it now.
 
all I see now is a set that includes pushrods..might want to call them and see if you can get them without, or call Harland Sharp( nice people) and ask if they will sell you a set of these they make for Mancini

Mancini Racing - Roller Rocker Arm & Pushrod Pkg
Sale price is more than regular price LOL. PLUS... I believe they are NOT Harland sharps. Not that I think Harland sharps are better than speed master but what do I know. I do all my racing from the couch.:lol:
 
Sale price is more than regular price LOL. PLUS... I believe they are NOT Harland sharps. Not that I think Harland sharps are better than speed master but what do I know. I do all my racing from the couch.:lol:

they are for a fact made by Harland Sharp, and carry a lifetime warranty from HS.
I asked them this very question few months back, talked to the son who now runs the company.
 
they are for a fact made by Harland Sharp, and carry a lifetime warranty from HS.
I asked them this very question few months back, talked to the son who now runs the company.
Good to know. Thanks for doing the ground work. The picture looks like all of the speedpro rockers and when I was shopping I did run into the harland sharps for the price you suggested but that deal dried up while I was shopping. I ended up with the pro comp SS rockers through B3 racing.
@HiFire, The Mancini site is a good place to do some shopping. They have some 273 style rockers for a decent price.
 
Last edited:
View attachment 1715930300
Happened to me two weeks ago on my daily driver Chevy truck. It’s not just spring pressure that causes it, wear also plays a big part. These have over 500k miles on them and this occurrence caused me to check the rest of them. I had 6 more that were very thin at the pushrod cup.
500K.....They should still be under warranty:lol:
 
Well to be more accurate it’s closer to 600k.
View attachment 1715930768
maybe I shoulda got the extended warranty.
:lol:

don’t laugh, for a time ( at least with Ram trucks) probably the rest, Chrysler offered a lifetime warranty on vehicles to the original owner. Came with just buying the unit free.
I know a guy who recently had extensive warranty work done on a 7 year old Ram with well over 200k on it.
 
they are for a fact made by Harland Sharp, and carry a lifetime warranty from HS.
I asked them this very question few months back, talked to the son who now runs the company.
Yes.. made by HS. I bought a set with the billet hold downs last year 1.6 ratio, have been sitting on shelf. Real nice looking set. I'll install with new Al heads.
 
Chrysler had a 50,000 mile power train warranty....not in 2003....in 1963.
 
Went to the Post office Saturday to ship and didn't know it closes at 12 :BangHead: My wife is going to ship them out this morning. I packed 2 intakes and 2 exhaust for you.They are in Echlin boxes but are my originals from 68 340 .
 
Thats a common issue with stock rockers, especially when you up the cam. I have seen 318 2 bbls do it too.
The replacement rockers from mopar performance were beefier in the pushrod cup but I dont think they sell them anymore.
I dont know if stock 340's were thicker but they did have a different shape to clear larger valve springs.
Btw, not all 273 rockers were adjustable. They switched to the stamped rockers around 68 or 69 if I recall.
I think that thicker MP stamped rockers was myth busted. 273's at a minimum for any performance build. Adjustable are great for preload too. Not sure why people still run stamped with all this "rocker geometry" doom and gloom. A set of rollers just sold for $75 here.
 
Just want to give a shout out to Rocket and Kendog for helping me out behind the scenes with parts for my truck. They went above and beyond to get me back on the road. Thanks to everyone else for the input and support. FABO is a great community to be apart of.
 
The aftermath of freeway speeds on a 68 340 with original rockers. The engine is in a 71 Sweptline. The springs are setup for a purple 484 cam. The cam is now a Howards 710931-12 with the 484 springs. Planning on replacement rockers from Mancini. Would like adjustable rockers but money is an issue. Anybody have pos/neg opinions on there rockers? Thanks everyone for your help.

View attachment 1715928757
Your rockers were prolly weak just like mine were. I am running a 509 purple cam in my 340 with stock rockers / springs and I had the same thing happen so I just replaced all rockers and springs with new stock rockers & springs and 2k miles later I have had no issues..
 
-
Back
Top