Lifters not staying seated in block when installing push rods

[Dres Garage]

Hello everyone I am at a complete loss with my build. I decided to upgrade my hemi 212 with billet rod fly wheel and piston also installed hot 265 cam and 26 lb valve springs. My issue is I can’t figure out how to keep the tappets seated all the way in the block when putting the push rods back under the rockers and when I do it sticks out I’ve rotated the piston to top dead center I did all of the lashing to 0.003. To me it seems that the stock rods are too long but I’m seeing that people run stocks rods with my cam and springs with no issue someone please tell me what I’m doing wrong

This pictures shows the tappet position after steating the rod under the rocker arms.

Ps I’ve been told that I must install cam first and then bolt side cover then install rods I did that made sure to lash properly and when I went to start had some kick back do some diagnostics and removed the head to find the rods unseated

 

[Whitetrashrocker]

Order of operations.
Cam has to go in first, and side cover installed before the push rods or valve rockers.
Use some grease to hold the tappets up if you need while installing the cam.
Once you have the bottom end buttoned up, push the tappets with the push rods and then set your valve lash.

 

[Hellion]

Use some grease to hold the tappets up

I use engine assembly lube (Lucas brand) but I have heard petroleum jelly (Vaseline) is a good substitute as it will properly break down and dissolve into the sump oil or is otherwise compatible with everything.

 

[Kartorbust]

We use this stuff at work. Works well for modern automatic transmissions with low viscosity fluids.

https://www.napaonline.com/en/p/BK_7652615

 

[panchothedog]

What WTR said in post # 2. 1st crank, rod, and piston. Next insert lifters into there bores. Use some grease to hold them into place, or even turn the engine over. Next install and properly orientate the cam. Install and torque side cover. Now install the cylinder head. Now install push rods and rockers. Not a bit unusual to need different length push rods after installing an aftermarket performance cam.