oil pressure guage install help needed

[tommie]

i have been putting a small block chevy in place of the straight 6 that came in the truck. i want to hook up the factory oil pressure guage, but the fitting on the line to the oil pressure guage is different than the hole in the block on the small block chevy that i put in.

does any one know the thread size of the oil pressure hole on a small block chevy? i guess that it is a pipe thread? but not sure of what size...

and does any one know the thread size of the line for the oil pressure guage, where it hooks up to the block on a straight 6?

i was wanting to go to the auto parts, or hardware store and buy an adapter fitting so i could use the stock oil press line for the straight six with the small block that i put in it.

i am sure some one has done this........

any suggestions

thanks
tommie