3/8" x 24TPI thread on one end and 1/2" x 20TPI on the other end

SKU 004587 Lowbrow Customs Frisco Mount Sportster Gas Tank - Super Narrow - 1

The stock caps are too tall and don't allow for a handlebar with a wider base

All components in this kit are proudly made in the USA

and the rear sprocket is 7075-T6 certified aero space grade aluminum for long life and light weight

#7350-15 Acorn Primary Cover Screw Kit 1971-Up & All 4 Speed Harley-Davidson Big Twins - Chrome Plated Petcock Thread_In-Line 3/8" x 24TPI thread onChrome Plated Acorn Primary Cover Screw Kit Fits Harley Davidson Big Twins 1971 up All 4 Speed, Made in Ohio, USA.