My supervisor asked me to convert my compensation from an hourly employee to a salaried one. I am in dilemma if I should accept this or not.

I am an IT professional and overseeing a fairly large project. I was hired as an entry level developer but I quickly learned much of their processes and bumped me up in responsibilities but without much pay increase(~4% total in last 2 years).

I will be launching my project in couple of months and it will require me to work a lot. As a lead, I also manage several other developers and I will be required to work overtime (~ 5 hrs each week)

I was hoping to make some money during this process. I would give the company what they want and also make some money. It was a win-win situation.

Now that the manager has offered a salaried position (with 4% increase over my current salary) that doesn't pay overtime, I am a bit confused. There is nothing that encourages me to work over 40 hrs. I can just do the regular 40 hrs, be an average employee and launch the project at the normal pace. As an hourly employee, currently I have an incentive to work past 40 hrs to get into overtime and launch the project faster.

I would love to know some ideas if I should accept this offer or not?