Should there be a coil spring insulator on the bottom?

I am working on a 2000 Chevy Silverado 1500 5.3
2wd. I replaced the lower control arm on the
passenger side but I can’t get the coil spring back
on there’s a rubber insulator on the bottom of coil
spring that is stopping it from sliding in. Do I have
to have that insulator on the bottom? I tried to see if
I can buy a new insulator for the bottom but I can’t
find one. So should it really be on there