[TR] TR4 manifold Studs

[Chris Kantarjiev]

The original exhaust manifold studs were copper coated and came in multiple 
lengths. You might try sourcing the shorter ones from TRF, but if you end up 
using "generic" ones, please be sure to use anti-seize before installing in the 
cylinder head. The factory nuts were "tall" and made of brass; those got hard 
to find and I started using normal stainless hardware to avoid corrosion 
problems over the years.