I bought a long block AMC 360 from Twilight(Auto) Zone. The brass fitting from my core that is a 90 degree angle out of the block doesn't fit the hole nor does the 3/8 male end on the new sending unit. I got the sending unit from summit with new gauges. The hole in the block appears to be for a 5/16. No one in town has a step down from 3/8 to 5/16. Nor does anyone have the stock sending unit but the one from my core was 3/8 also. Anyone have any ideas? Twilight Zone was no help. My exhaust manifold bolts were not tapped the same either. What's up with that? I know I could just tap the hole to 3/8 but the engine is already in my jeep and its brand new. I didn't pay $1000 to drill and tap holes. I need help. My buddy's 304 has a similiar brass fitting to the one I got from my core engine. Why isn't anything easy? Thanks for the help.