Update.

I got the adjustable pushrod.
The pattern has moved more to the center. The sweep is tad larger.

Left valve- 7.100"
Right valve- 7.150"





Both valves- 7.200"



I think according to this I am real close.
http://www.pontiacstreetperformance....traingeom.html

Any comments?

 

Go to 7.300 and turn it by hand and see if it don't move it more to the intake side. It should at least show ya which way to go.

 

Unless you are using some exotic valvetrain parts I am pretty sure that on an LT-1 (same idea as a SB Chevy) you should be getting the same length pushrod for both the intake and exhaust.

 

No, no,
These are only for comparison for what looks the best.

I will be using the same size for all valves.

I think the 7.100 looks really good.

I went 7.250" and it was clearly in the wrong direction.

 

OK ya already been there.
Shorten them .050 and see if it moves or narrows up.
Not knowing what has been done to your combo it is hard to say which. If 6.990 puts it in "center" and the narrowest(.060) ya can get it then that's what ya want to run,NO MATTER what is SUPPOSED to be "right". It's what is "right" for your set up.

 

OK ya already been there.
Shorten them .050 and see if it moves or narrows up.
Not knowing what has been done to your combo it is hard to say which. If 6.990 puts it in "center" and the narrowest(.060) ya can get it then that's what ya want to run,NO MATTER what is SUPPOSED to be "right". It's what is "right" for your set up.

 

Okay.
I shortened another .050"

Left valve- 7.050
Right valve- 7.200 (stock) for reference only



This appears to be dead centered on the stem and slightly wider sweep than stock. I can only assume that the CC Pro-mags are necessitating this .150" shorter pushrods.

Does this sound right?

 

Shorten some more and see if it will narrow up. It is trial and error and ya need it as narrow as possible to prevent guide wear.
Looking better though with the 7.005.
Make sure the rocker doesn't bottom out on the stud and it is NOT hitting the retainer or spring.
DON'T worry 'bout the length.

 

1racerdude
Thanks a million.

7.000" moved the mark up and off center, so either 7.050" or 7.100" it is.

Why do you think the Pro-mags are nescesitating these shorter pushrods?
My heads are stock with only LT4 springs. I have yet to hear anyone encounter the same problem.

 

Is the block stock? Did ya change gasket thickness? were the heads surfaced?
ALL these little things mount up and it could be part rocker arm too. It doesn't matter the length as ya can get ANY length made or off the shelf usually within .025. It's what is the correct geometry.
If ya keep going shorter it may narrow it up too,but no guarantee. It may be the best it will get.
How wide is the mark?

 

Block is all stock including gaskets. Heads have never been removed.

 

Well it would be safe to say the rockers OR cam is doing it.
Read my above post and let me know.

 

The mark is .105" wide.
Stock cam.

 

Try to narrow it up by shortening up a little more.

How many out there have the wrong geometry seeing what ya ran into,a bunch that said so-n-so is running a 7.xxx length so they get that length.
Things like you are doing NEED to be checked but most don't bother.
To make sure ya are correct I would check another cyl.

 

Okay this is a new cylinder.

Left valve- 7.100" PR with .85" of sweep. Slightly below stem centerline.
Right valve- 7.050" PR" with .105" sweep. Perfectly centered on stem



So its down to what is higher priority, more centered up or lesser sweep.
Thanks