Heavy Club

I have seen an ad on TV by Butch Harmon for a regulatioin size driver that has a weighted head. I am trying to get back to swinging through the ball and I think that with that type of club I could develop some muscle memory to help me follow through. Trouble is I am cheap, so If I picked up an old used club, drilled a hole in the top of the driver head and filled it with some substance to add weight would that do? Or is there something else I need to consider like the placement of the extra weight?

The only concern I'd have is that the shaft will play weaker with a heavier club head.

I see your point, but as I am using this just to "groove" my swing, trying to get a full follow through into muscle memory, why should the shaft stiffness be an issue. I can see if I want to his balls with it. I see this as nothing different than using a weighted baseball bat to warm up. Am I missing something?

If you just put the weight in the head the flex will be very soft, as mentioned and more importantly (I think) the balance will be off.

Golfworks sells a heavy shaft for making clubs like this.

I used an old driver and added weight to the head and shaft to try and mimic the Momentus driver and it was really only good for warming up.