Manifold stud and nut kit that could help take the frustration out of fitting after market extractors and inlet manifolds. The manifold studs are 3/8 UNC on the short side and reduced to 5/16 UNF on the long thread side. The AS022 steel tabs still have a 3/8 clearance hole that allows you to move the tab left to right and up and down. The 5/16 brass nuts are smaller than a standard 3/8 unf nut so a smaller spanner can be used.
Please be sure to read the description
The kit includes
2x 3/8 unc extractor bolts with reduced head
2x 3/8 spring washers
6x 3/8 unc reduced to 5/16 unf manifold studs
6x 5/16 spring washers
6x 5/16 unf brass nuts
6x 10mm assorted steel retaining tabs with 3/8 centre hole
A few hints that might help when installing you manifold, extractors and stud and tap kit. Buy a 3/8 unc tap to clean out the threads in the cylinder head. use a quality thread sealer/ low grade thread locker on the studs into the cylinder head. Using a stud remover installer can help stop damaging the threads when installing the threads. If the exhaust manifold/ extractors and intake manifold are different thicknesses you can buy 3/16 key way steel pretty cheap and tack weld it to the tabs to keep the tab height even. The time spent aligning and getting the clamps to sit right will give you a better seal on the gasket face. We would suggest when using the reduced size studs that a manifold brace be used once you have the intake and exhaust manifold bolted to the cylinder head.