Optima doesnt fit?
 

I just picked up an Optima 35 series battery it doesnt fit.

I saw the DIY but it says use a space from the OEM battery, mine doesnt come with a spacer.

Anyone have ideas?

Could I use a 34 series?

My OEM battery didn't use a spacer either but the Optima came with one. It was actually the shipping cover over the top of the battery. Try going back to the place you bought it from and see if they have one; or you could always try a piece of plywood.

No place around here carries the one I need so I will be ordering this online ths weekend.

plywood works fine just make sure you dont completely obstruct airflow around the bottom of the battery