Kenny:
Welcome to the board.
As posted above, you might want to contact Mike Baker @ IHRA for the latest factored h.p.
My Pure Stocker ended up being factored lower than a regular Stocker 302 rating of the same year.
I just wished IHRA would post their latest factored h.p. ratings for each combo on the net.
And yes...it's factored h.p. times class weight break plus 170lbs= minimum race weight.