I am having a headache trying to tighten up my oil dipstick. There is a bracket on there that you cant get to easily from the top. The last time I changed out my plugs, I worked it a little loose. I tried from the top to tighten the bolt, but no luck. What size is the bolt 3/8 ???? Where is the best place to get to it so you can tighten it...from the bottom I imagine....The GM engineers need there as* kicked for designing the passenger side engine bay on these car.

 

Yes that bolt should be approached fron underneath the car. Its either a 3/8" or a 10 mm.

 

>remember that most if not all fasteners on these cars are metric not SAE (yes there are some sizes that are the same like 10mm and 3/8",13mm and 1/2", etc.)

 

Actually, anything that bolts to the block on an LT1 is not metric. 10mm and 3/8, 13mm and 1/2 are not close enough to be called the same in my book. I would never interchange tools for those as you could strip the heads.

 

>I did not know that. so what size are the head bolts, oil pan, oil pressure switch, or the accessories bracket fasteners? I don't remember using any SAE tools to remove or replace these items (hope I didn't strip them) .

 

That bolt is reachable from underneath. If you need extra room you can remove the starter, it's simple enough.