Nigel the 1977 MGB Duplex Timing chain installation

Replacing a single row timing chain with a dual row chain in a 1977 MGB. installing new tensioner, reconditioning timing chain cover. Confirming the difference in valve timing from single and duplex gear sets. Parts used: 18G-GK timing chain kit https://abingdonspares.com/products/m... Crank shaft sprocket 18G-GK https://abingdonspares.com/products/s... Camshaft sprocket 18G-GK https://abingdonspares.com/products/s...