1973 C-10 350 engine, not original previous owners twice removed installed it. I am trying to address leaking oil around the intake manifold bolts at the 3 and 4 position on each side of the manifold. This was a botch job and it looks like they used whatever bolts they had in a coffee can rolling around the garage. One bold is 1 5/16 inch course threaded up to the last 1/4 inch . One bolt is 1 3/16 inch and threaded all the way up. No washers. I ordered intake manifold bolts that were supposed to be for this model engine. 1 1/16 inch (MR Gasket #6080MRG). I wanted to get an opinion. Is it safe to use these bolts, the manifold appears to be approximately 1/2 inch thick? Or should I seal up the bolts that were in there, add washers and pray?