Oil pan leak question

[rhm63]

Hello all. I have been lurking around this forum for about a year. I have found many answers, but I finally have a problem that the search button hasn't been able to answer.

I have my grandfather's 1963 C10 pickup with a 230. (I think). It was rebuilt in the late 80's and he claims that is the "big 6" but it is not a 292. Maybe converted to a 250?

But back to the question at hand. I have it running smooth. But there is an oil leak from the front of the oil pan. The gasket was replaced with the rebuild, and appears to be in good shape. But it leaks from a bolt hole with no bolt. From my shop manual it appears that there should be bolts in these holes, but I dont have any. See the pictures. You can kind of see (by the shinyness of the oil) the hole that the oil is leaking from.

Should I have bolts there? There are not holes in the gasket. Should I cut them and add bolts? Can Hi-temp silicone seal this? I really dont want to have to replace the entire oil pan gasket. But I dont want to half ass it either. I really need some advice on this one. It is almost the only thing keeping it from driving.

Thanks