I've installed an Optima Red Top in my '68 RS/SS Convertible, and am having an issue with the stock battery hold down not working. The Optima fits under the front lip of the tray just fine, but the clamp tips up when slid all the way forward to meet the side of the battery, and subsequently doesn't hold it down tight. I'm thinking about fabricating a new clamp out of flatbar that would reach a little further forward, and would remain flat (level) when the bolt is tightened. Does anyone know of a ready-made solution? I know that Optimas are often shimmed up to make them work with stock hold-downs, but that doesn't do the trick in this case as the flange around the bottom of the battery doesn't fit underneath the front lip of the tray with the shim in place, and it doesn't seem like it would solve the problem anyway. I think the bigger issue is that the body of the battery isn't quite deep enough (front to back) to engage with the clamp properly.

Any ideas are appreciated!

 

Make a hold down out of bar stock shaped the way you need using the same bolt attachment as stock if the Optima has the lip on case like a standard battery.

Not quite visualizing what the Optima fit thing is as I use a 78 series, side post, standard battery which uses the stock hold down.

 

I put a piece of 3/8 key stock between clamp and battery, short enough so it can't even be seen.