Ok so here goes:
Fit the original timing gears and a NEW CHAIN and TENSIONER. That will then make sure you're in the right ball park to begin with.
Then (without moving any of the gears) carefully remove the Camshaft Gear and fit the Vernier Pulley.
Next fit the Timing Disc to the Crankshaft (Fit disc with the Pulley to stop you mashing the Disc up from the bolt). Do the bolt up TIGHT (you need to rotate the engine anticlockwise sometimes & it's annoying when you do that & the flippin bolt comes undone)
Now fit the DTI Gauge onto the Block and position the tip over Piston #1 (Closest to the Timing Chain). Then wind the crank round and note the highest position of the piston on the DTI gauge. That position is then at TDC. You then need to bend your piece of wire coathanger around a bolt, and bolt it to the block. You then need to bend the wire to point to the TDC mark on the Timing Wheel.
There is a certain amount of "Dwell" on a Crankshaft (where the piston is at the top of it's stroke) and that can be seen when you're using a timing disc. If you CAREFULLY rotate the crankshaft, you will notice that you can rotate the crank maybe a couple of degrees without it moving the DTI? Well that's the dwell. You need to make sure you notice where the dwell starts, and where it stops (measured in degrees on the Timing Disc). The middle of these two positions is TRUE TDC. When you find this middle position, again tweak your bit of wire to point to TDC on the Timing Disc.
Now it's time to set the Camshaft Timing. Remove the DTI gauge from measuring the head of the piston, and adjust it to measure the top of the camshaft Follower on the Inlet Valve of piston #1 (second Follower from Timing Chain). I imagine this will be a little bit tricky so would welcome some suggestions from other members here on what to use to make obtaining that measurement easier? A small metal block for example?
Anyway, as soon as you have your Camshaft Follower measurement set, you can rotate the crankshaft to find the point at which the camshaft follower will come no higher (ie you're at the top of the cam). You now need to notice the measurement on the DTI gauge and write this down. (Say it's 8.1 for example).
Next comes the part where everything starts to make sense....! Turn the engine back to the TDC position and then look in the leaflet that came with your cam to get the correct timing position in degrees (say it's 112 ATDC - After Top Dead Centre). Now rotate the engine CLOCKWISE until you get to that position (112 degrees).
Now you need to undo the bolts which give you the adjustment on the vernier pully and rotate the camshaft independantally to the crankshaft (making sure you don't turn the camshaft from TDC) until you find the highest position of the camshaft follower again (remember in this example we measured it to be 8.1).
Then tighten everything up and you're timed!!!!! Check everything a couple of times to make sure you're right and adjust where necessary. (Rotate the engine a couple of turns and then find 112 ATDC and make sure you still have the 8.1 on the dti)
Sorted.
You then need to get a hammer, and get EVIL on the timing chain cover to give yourself clearance.