Today when I took off my rocker arms, I saw my current 7.400" pushrods are long. (Mark wasn't at the middle of valve). Anyway I took off 2 lifters (in/ex), replaced the Morels and the same (7.400") pushrods. That was longer than before. So I adjusted one of my adj. pushrods at 7.300" and the other one at 7.200". I cranked a few turn and I looked top of the valve I saw 7.200" at the middle. and 7.300" was still longer. I tried again and I adjusted at 7.150" and the other one at 7.250". After I cranked I looked 7.250" is longer, and 7.150" is also in the middle. I decided to go with 7.200" lenght.
(((The mark was .075 wide)))

There is 0.200" changes after I replace Morels, but before Morels those 7.400" was also long, so I think from Comp R's to Morels 0.100" shorter pushrods needed.

For Morels, I adjusted 1/2 preload after zerolash. The interesting thing is my Comp R's were setted at 5/8 preload after zerolash

 

7.2 is stock length....

 

Stock lenght for stock engine.
My heads' valves are 0.100" longer, so add 0.100" for pushrods. But on the other hand my heads are milled. Obviously 7.400" pushrods were too long, the mark were downside of the center. So after I replaced Morels, 7.200" is the best lenght I think. I will try for another cylinder in Monday, but I don't think I will need 7.150" or 7.100".

 

Go with what the pushrod checker gives you. I'm sure the 7.2s will do the job if they give you a good centered pattern.

 

Yes thanks to Larry (1racerdude)!!!

If I calculate the numbers it also makes sense.

Stock pushrods= 7.200"
+ 0.100" (0.100" longer valves)
- 0.050" (milled heads)
- 0.050" (Comp to Morels)
= 7.200"

Yeah it is very rough calculation, but I tested and approved. Monday I will take photos when I do this for another cylinder.

 

By the way I didn't use solid lifters, I cranked it and brought the 1st cylinder to TDC, so in/ex valves fully closed and I replaced the Morels, and pushrods then cranked again from Damper. Do I need solid lifters when I measure by using this way ??

 

I used the same 7.250 rod's I used with my Comp 'R's. they checked out perfect. I am using link bar lifters. If you are not then this may be where the issue is and I think Morrell GM lifters are desighned for late model LS1s with a different cup Hieght.