I had a bit of trouble with one of the exhaust valves which was slightly bruised halfway up its stem and so too tight in its guide. Polishing the offending part of the stem in the lathe with some very fine Emery paper did the trick. The next task was to assemble all the valves and tappets in place and make sure there was enough clearance for the cam to pass through its bearers without interference.

This was done without the valve springs in place. You don't want to find out later that the cam is obstructed. I had set the valve guides a 1/16" lower than specified to ensure I wouldn't get into trouble. Once that was confirmed OK, the valves were assembled with the springs and tappets tightened all the way down.

I'd forgotten the sequence since the last time I did this, and it took me half an hour of struggle to remember that the special valve compression tool was needed. This consists three plates, each with four stepped cut-outs which sit on the oil and spring retainer cups and when tightened down, compresses the springs to allow the tappet to be screwed all the way into the valve stem.

For the valve spring compression preceding the insertion of the camshaft, I have to add a specially made metal block to each of the plates. These blocks spread the load equally over each of the valves and prevent the plates from bending - the springs are very strong. You may recall that one of the studs in the tool broke away from the base plate when I dismantled the old head and I had to weld it back on again. I obviously didn't do a particularly good job as, applying the final tweak - ping! - off it came again.

With all the tappets just a gnat's clear of the camshaft bearing shells, the cam slid into position with ease. The lower of the two shaft retaining plates at the gear end must be inserted before the shaft is fully in position. Once that's done, the top plate can be added and the compression plates removed. The mating bevel gear and plate assembly is then bolted in - again a bit of a struggle to locate the bolts as you have to push against the shock absorber in the cam bevel gear. There's no special sequence to set the tappet clearances; all you need do is adjust to 0.015" on the back of each cam when the engine's hot. I decided 0.016" to kick off as the engine would be cold.

With a new head gasket slipped on over the studs, the head was then ready to be lowered onto the block after checking that no nuts, washers or foreign objects had fallen into the bores - I've been there and have the T-shirt; there's a lot of worrying noises on first start up.

One of the annoying features of the head is that after fitting the camshaft shock absorber on the rear of the shaft, one of the head bolts is impossible to get at. I always give this one a couple of extra pounds of torque to save me removing the shock absorber when re-torquing the head. The big bolt which holds it in place is accessible through a hole cut in the firewall.

It took a couple of days to get the final assembly right - a leak from the thermostat housing was a nuisance - and on first start up I had quite a few adjustments to make to the carb and points. The distributor bush had a bit of play in it, so I closed the points gap up a few thou to compensate, and the jet body spring was restricting the main jet travel, so I found a lighter spring which put the jet level with the floor of the venturi.

And now the car runs like a dream, and with markedly improved performance. What's more, there were only three bolts and four washers left in the tin when I'd finished. Result!