Well, I used an adjustable pushrod to find out my pushrod length. I put in the pushrod, torqued the rocker to 22ft/lbs, then lenghtened the pushrod until I got zero lash. Out of curiosity, I did both the intake and exhaust and got 7.717" for the intake, and 7.707" for the exhaust. I feel the difference may have been due to human error, but the exhaust and intake do have two different lobes, XE and XE-R, respectively.

So, now adding good old .060" for preload, that gives me 7.777" for the intake, and 7.767" for the exhaust. Now, what off the shelf length pushrod would be a good choice? I'm thinking Manley 7.775" pushrods, 3/8" diameter, .080", 5/16" ball ends, hardened chromemoly, part number 25833-8. Are there any other possibilities? Thanks!

 

Personally, I'd look into a 7.750", but I like the lash a bit on the loose side. Always seems to run better for me. I've seen people run stock rockers at .020", but they did make more noise. You could always use the 7.775 on the intake and a 7.750 on the exaust. That would give you .58" on the intake and .43" on the exaust.

 

What lifters are you running.... Also factor in about .010 for block assy. growth

 

Lifters are COMP OE replacements.

 

IMHO the 3/8" Manley at 7.775" length looks to be the right ones if you did the measureing correctly. You can also look into Manton pushrods. They make some of the finest and strongest going and will make them to any length. Those are the ones I will be using on my buildup.

On 2nd thought are not the stock LS1 pushrods 7.4" long? So, is this for an LS1.

 

I need the pushrods ASAP, so off the shelf length is what I'm looking for. They are for an LS1 block using LS7 heads, thus the difference in length.

 

You want .060 to .100 for preload and I would err on the high side do 7.775s or 7.800s even better.

 

.100" of preload!! No thanks, I'd like my valves to close Although, getting 7.800" pushrods is a hell of a lot easier than getting 7.775" pushrods.

 

Do search, .060 to .100 is recommended with .080 considered ideal, I could be wrong but I believe that's accurate.