I have to replace a missing timing pointer on my 79 Spider. I have the Pointer, but need to know what size bolts it takes to attach it. Looking at where it goes on the water pump, I am thinking I need to take out the radiator to get access to install it, unless I can get to it from under the car ? Any suggestions would be appreciated, before I start tearing into this. I want to complete this in the most efficient way. Thanks.