trying to pull the harmonic balancer - questions

[72kat]

Let me preface this with I know I'm dump. I'm just learning.
Have a 72 chevy c10. Pulling the harmonic balancer.
Have removed crank pulley etc. Connected puller to harmonic balancer.
Have removed radiator. When I try to put my impact on the end of the puller,
I can because of the lower radiator support. I am being dumb, or do you have to also remove the lower radiator support?

Thanks and be gentle.