Hello I have an electric boiler being fed wit a 150 amp 4 pole breaker and I want to split it to 2 double pole breakers what size double pole breakers would I need to equal the power

Why?

If it is working properly, why change it. You gain absolutely nothing by changing the breakers.

It's not a 4-pole breaker. It's a two-pole, it's just a weird design.

I'll also ask, why are you wanting to do this?