Two-stage snow blowers are designed to move large amounts of snow. The more snow that falls, the larger the snowdrifts.
As you muscle through the deep snow, your snowblower may occasionally bump up off the ground, causing you to miss spots while clearing. Front weight kits serve two important purposes for two-stage snow blowers.
Front weight kits are typically bolted onto the top of the snowblower bucket. The extra weight simply keeps the snowblower firmly planted on the ground. This prevents the snowblower from riding up as you are clearing snowdrifts.
Your snowblower is a lot like a seesaw. The weight is counter-balanced on the back wheels.
When you add a heavy snow cab to the back, the weight is no longer balanced. As a result, the snowblower tends to kick up much more often. If you get a snow cab, you probably should consider a front weight kit too.