Tecumseh HMSK105 revving high

Snowblower engine to which I changed the carburator (including mount gasket). Revs out of control.

Governor linkage is moving normally. To confirm the Governor gear wasn't the issue, I unhooked the Governor rod from the carburator and the engine will rev high even with the butterfly stuck in idle position

My guess right now is its running lean because of an air leak and since I changed the carburator mount gasket I'm assuming the leak is from the intake manifold gasket on the engine?

What would be the best way to confirm where the leak is coming from?

Going to order gasket tomorrow, but wondering if I may have missed anything in my troubleshooting?

Thanks for your help!