[Question?] newbie horse manure soil mix

[bobsledgehammer]

Hey!

New here to this awesome forum, great reading so far. Only thing was I couldnt find much about horse manure soil mixes. I am wondering if this soil mix is acceptable and will produce some nice hunnies!!

2 part native soil (clay)
2 part perlite
2 part worm castings
2 part horse manure (stuff is really dry and has a dirt smell to it, 1 years old +)

apparently with the worm castings and manure, the n-p-k is rated at 1.3-0.8-0.9...Is that enough? If not, what can be added to make it super duper??

thanks!