Re: {Chrysler 300} 300F Pushrods & Rocker Arms

[John Grady <jkg@xxxxxxxxxxxxxxxxx>]

I did not know specifically about this on B block  ; but ran into same thing on 392 , i believe (from memory ) hydraulic are 5/16 and 300 adjustable are 3/8” at rocker , possibly at solids too . Also which way around cup vs screw with ball into cup on push rod . 
1/4 seems awful small ? Is that right ? Or my description here may be off 1/16 . 
So for instance modern comp hydraulic lifter performance cam with 300 heads  ( the 392 today has limited choice of cam )so not an  unreasonable choice in 2023 to get a modern grind,  one needs I think 3/8 “  at one end 5/16 other . But need others to confirm 
I bought a 300D 392 “ built by an “ expert pro “( and all that bs ) in California , about how great he is,  for top money a few years back which had small tips on 300 heads at  both ends ,lucky I  found it . It would have eaten up valuable real  300 parts . Another case of a bumbling rebuild. 
I am sorry for lack  of specifics , don’t want to say wrong thing , and seat height in lifter gets into this too . The length can vary then which brings up where is rocker adjustment screw when you measure , ( I picked middle of range ) and —big warning - the larger end does not go all the way into a small cup while measuring . I picked middle from looking at factory D heads , as found. length varies especially with hydraulic  roller 

Yet another thing is where on  ball/ push rod end  do you measure . Seems to be two standards tip to tip and center of ball ( which is  engineering correct for exact pivot point ) which makes it vary slightly depending on radius of a given tip . arrgh   

I made several expensive mistakes trying to sort all this out , Fred asks a very good question here . 

Maybe after getting real info we can document some of this on both engines under “push rod , rocker , lifter variations “? 

related , is the small oil hole available in new lifter faces  (~.013 ) good or bad ? (maybe a solution to a “non problem “, or maybe improved life with oil issues - as claimed -/ or causes problems ) I wavered around . Still do . Someone has a tiny slit down one side now too , same issues   , may be better or worse . 
Leaning more to leave it alone . 

Smith Bros  custom pushrods simply the best , many options , two day turnaround on custom set , beautiful . Especially so , if the right length 
jg 

Sent from my iPhone

> On Jul 31, 2023, at 11:07 AM, Frederick Grossi <e55grossi@xxxxxxxxx> wrote:
> 
> Hello Group,
> 
> I am having my 300F 413 engine rebuilt by Timo Tanskanen, a restoration expert who regularly advertises in our newsletter.  He has some questions about the pushrods and rocker arms of this engine that he has asked me to pose to the group because he has run into some issues that are causing delays in my engine rebuild.  He states that the factory manuals don’t seem to have clear enough information and all of his “go-to” guys can’t seem to be able to say for sure, have moved on or passed.
> Basically, Timo would like to know if anyone has a good photo(s) and/or clear specification info regarding the original pushrods and rocker arms.
> 
> 1.  What diameter are the upper and lower pushrod tips originally used in the early RB (383/413) engines?  Photos?
> 
> 2.  What is the OEM cup size on the pushrod side of the rocker arms, 1/4”, 5/16” or is/was there possibly two different sizes available for/used in early RB engines?  Photos, especially if two different sizes, preferably shown side-by-side in resolution photo or two?
> 
> Thank you and much appreciation,
> 
> Fred Grossi
> Pegram, TN
> 
> 
> 
> 
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