Another stupid push rod length question

[usraptr]

First of all I've watched every you tube video there is and read numerous articles on this forum as well as others on establishing proper push rod length, and still have a couple of questions.  First question, new build with new cam and lifters; do I need to soak the lifters in oil overnight before using the adjustable push rod length checker or does it make any difference?  Second question deals with pre-load.  I'm using the stock shaft rocker arm assembly on my build to save a little money as everything I've read said that it is more than adequate for my build.  Also, everything I've read/viewed about pre-load deals with adjustable rockers or say add .030 to .050 to the no lash length so I still confused on this issue based on the following.
 
To remind everybody, decked 440, Lunati hydraulic cam and lifters, Pro-Maxx (formerly Patriot) aluminum heads, torqued to 70 lbs with used Felpro head gaskets.

First of all I marked the top of the valve stems with a black marker as suggested.  Then with "dry" lifters, I adjusted the push rod checker to zero lash, with the cam lobs bottomed out, and then turned over the engine several times.  I removed the rocker assembly and the "witness" mark was dead center on the top of the valve stem which if I read correctly is where I want it.  I then checked the length of the adjustable push rod length checker against a stock push rod and they were virtually identical in length.  I then repeated the process using the adjustable push rod checker in the intake and the stock push rod in the exhaust.  Again, the "witness" marks on both valve stems were in the center. 

So first of all with all the mods to the engine, how likely is it that I can use the stock push rod length?  Will soaking the lifters in oil make a difference? Do I need to add ".030" or ".050" to the adjustable push rod length checker since the "witness" marks were dead center on the top of the valve stem as is? Again, sorry for the novice questions, but I know that proper push rod length is critical so I don't destroy my new engine on start up and  obviously I don't want to go there.

[cudabob496]

lotta smart people here, but also would not hurt to talk with Lunati

[Chryco Psycho]

oil soaking will not make a difference oil will not swell the lifter LOL .
 You may be able to get away with stock pushrods but you may need a lot stronger rods for the spring loads

[1 Wild R/T]

What Lunati cam? 701? 702? 703? If your gonna use stock rockers hopefully it's the 701. 702 is marginal with stock rockers & 703 is a bad idea....

When checking preload with hydraulic lifters you should disassemble the lifter & shim it solid so the cup is tight against the snap ring & won't compress.... Then with the lifter on the base circle of the cam & the rocker shaft torqued to spec, set  the adjustable pushrod for zero lash & lock it down so the adjustment can't change....  Unbolt the rocker shaft to remove the pushrod... Measure the pushrod & add .050 to that number.... Thats your correct length.. You should measure at least four locations & preferably all sixteen.... 

[usraptr]

1 Wild R/T, not trying to argumentative here but why do you say it's a bad idea to run stock rockers with the 703 cam?  I've read several magazine articles/engine build books and they all say that the OEM stamped rockers are strong enough and adequate for a street engine?

[Chryco Psycho]

I have seen them fail from spring load & punch a pushrod through the rocker arm
 just because you an get away with it doesn't mean you should

[1 Wild R/T]

Why is it a bad idea to run stock rockers with the 703? Well since the whole point of stepping up to more aggressive cam profiles is to open the vale quicker & higher....  Stock rockers have been known to punch pushrods through rockers with stock spring pressure, increase the spring pressure & that becomes more of an issue... The quicker acting ramps Lunati is known for increases the load on the rockers so not you have higher spring pressure & quicker/more aggressive ramps... Do what you want, I've run stock rockers with to much cam & mostly got away with it but never got the full potential from the engine either...

Funny thing, Lunati doesn't seem to make spring or valve train recommendations like other manufacturers they just sell you a cam & wish you luck...  Don't get me wrong they sell good cams but pretty thin on dded knowledge... Isky, Crower & Comp all have lots of technical info & recommended valve train upgrades.

Lunati sells springs, pushrods & rockers.... If you own a Chevy.....

[734406pk]

1 Wild R/T, not trying to argumentative here but why do you say it's a bad idea to run stock rockers with the 703 cam?  I've read several magazine articles/engine build books and they all say that the OEM stamped rockers are strong enough and adequate for a street engine?

It's not so much the lift but the velocity that this 703 cam generates. These factors cause stress levels beyond what the factory stamped steel rockers were designed for. Ductile iron rockers with cup and ball pushrods are cheap insurance, along with stronger/heavier rocker shafts. Cheap insurance IMO, you don't want any "weak links" in your build. I have found recommended valve spring data in the Lunati catalog. It's available online as a PDF download from their website. Here is the link:::

http://www.lunatipower.com/LunatiOnlineCatalog.aspx

Good luck!

[usraptr]

Thanks everybody for the replies and explanations.  Guess I'll be up grading to set of roller rockers from 440 source.

[1 Wild R/T]

Thanks everybody for the replies and explanations.  Guess I'll be up grading to set of roller rockers from 440 source.

Sounds like an invitation to bigger problems.... Why add rollers that if/when they fail tiny metal rollers get spread through your engine?  Theres a very good reason why lots of guys use Ductile iron rockers or step up to higher quality rockers.... In the lower priced stuff PRW Stainless rockers seem to hold up...  But then they aren't as cheap as they were a few years ago...

[Chryco Psycho]

I would stay away from Alum
 You are better of with Iron or Prw stainless & yeah the prie has gone up on Prw stuff

[dodj]

Funny thing, Lunati doesn't seem to make spring or valve train recommendations like other manufacturers they just sell you a cam & wish you luck... 

They do now. I sent an email to lunati last year asking them what they recommend for springs to go with my 703 and the responded with their 73100K2 springs/retainers and locks kit. Just FYI.

[usraptr]

Okay, Thanks for all the advice.   I've pretty much settled on the PRW stainless rocker arm kits.  Next question with the Lunati 704 hydraulic cam and lifters do I want 1.5 or 1.6 ratio?  As a reminder, 440 stroked to 512, .30 over, Pro-Maxx (formerly Patriot) 84 CC aluminum heads, Edelbrock Performer intake (Shaker hood, can't do a taller intake) and Quick Fuel 880 CFM carb, vacuum secondaries, TTI 2 inch headers.

[734406pk]

IMO 1.5 ratio.

[Chryco Psycho]