Inside the box with the new balancer I bought there were instructions to boil the balancer in boiling water for 15 minutes and it would expand it enough to intall wiithout a tool. It said it harmed the balancer in no way.

I didn't need to do it as I used a grade 8 bolt to pull it on, but the boiling trick may help you get it seated easier. Mine was also on a sbc.

Don