You gotta see this ......

[trebor75]

Thanks again for the links and info guys. I will look at all the options you posted.

 

[nm9stheham]

Don't know anyyhing about the cam.

Dang.. that is not good for getting a good handle on this. Any chance you can borrow a dial indicator and degree wheel and look at the lifter max lift and .050" duration? (Both measured at the lifter, not at the valve.... If you do this, you'll need to pull rockers and use a pushrod to follow the lifter movement with very little pressure on the lifter to avoid any lifter compression....or better yet, put in a solid lifter.)

 

[Killer6]

Don't know anyyhing about the cam.

Lol, then You'd better find out! One of the #1 things to do to a stock Mopar valvetrain is to
shim the shafts to reduce the lifter preload, which requires checking such, often times the
pushrods are too long to start with.....and this prevents the lifters from holding the valves
off the seat and increasing the actual lift at that moment by "pumping up" when oil press.
is high & the springs start to lose some control of the valve(which always happens to some degree). Without knowing where You started, and where You're at, You shooting blind, which
usually is bad odds in engine building...........

 

[Killer6]

MP sells HD rocker arms with a heavier guage pushrod pocket, but for that price Id just get some $150 273 ductile iron mechanicals here on FABO.

Rich Ehrenburg checked & dispelled this a long time ago, mic'd pockets & tested hardness. The MP rockers were no better than the stockers....................

 

[pishta]

Maybe these can handle it..............

Fits: 273/318/340/360

These heavy-duty rocker arms from Mancini Racing are quality replacements for your factory originals. They feature thicker cross-sections in the pushrod socket. Left and right refer to rocker offset, not to the sides of the engine or cylinder head.

Includes 16 heavy duty hyraulic rocker arms

............
Mancini Racing Steel Rocker Arm Set, 1.5 Ratio

yeah, see post #16.....$99 aint bad if your all set up for hydros....

Rich Ehrenburg checked & dispelled this a long time ago, mic'd pockets & tested hardness. The MP rockers were no better than the stockers....................

bummer, but they are brand new , not 41 years old....

 

[nm9stheham]

BTW. I am ASSUMING that the Mancini types that Daves69 and I linked are different from the MP ones, and indeed have heavier pockets.

FWIW, this is NOT really an Edelbrock specific issue. Use the same cam, the same rockers, the same spring rates, and run the same RPM's, and the result will be the same. The only difference could be IF the Edelbrock valves/retainers/locks/springs are heavier than, say, in a J Head.