That looks right. Getting those side seals all the way down is the hard part. I leave the side seals longer than the cap and work the cap up-and-down so they sit all the way down in the block.
Also use a smear (not much) rtv between block and retainer ends. Make sure crank/seal have lube so the seal does not tear on startup.

That Summit windage tray looks a bit different than the Jegs version? The Jegs version has slips on the side, and that Summit version looks like it has holes?
I used the Jegs version of the windage tray on my 4.25" stroke 440 using an old Mopar Performance Street Hemi oil pan (and the viton rear seal like in the photo), and it sealed great!
Really happy with the results. no drips at all.

On the other hand, the 4.15" stroke low deck stroker was built with the standard rubber rear seal, and sandwitched factory type windage tray, and it is leaking pretty bad, but the milodon oil pan has taken some damage too.
Fixing that oil leak is just another project to get done. I already bought a replacement oil pan, and the Jegs molded windage tray.