Is TDC on the 4.2 XK set on pot one (firewall) or pot six (radiator) when setting the bottom end timing?

I have set TDC on pot six closest the radiator (timing marks on crank pulley set to zero), set both cams with the correct cam setting tool, chain is tensioned however when I rotate the engine about a quarter turn it locks up and looking at it I think its getting contact on pot 5 (from memory, could be 4) between the piston and exhaust valve.

The head was off and rebuilt and I am trying to set it back up again.

The only thing I can think of is TDC should have been set at pot one (fire wall) but both 1 and six are TDC at the same time, arnt they?

Any ideas?

 

Sorry guys, just to add this is the latter 4.2 with the four bolts on the cam sprockets, but I think they all time up the same anyway don't they?

 

From the manual :-

"By reference to the timing marks on the crankshaft damper,
or in early cars the timing marks on the flywheel.
Turn the engine until No.6 piston is exactly on Top Dead Center
with the distributor rotor arm opposite No.6 segment"

You are correct in that Pot 1 & 6 are both at TDC at the same time, but 1 will be on the exhaust stroke.

If you are getting contact with the valves, you have not got the valve timing correct so double check this first.

 

And just to add, number 1 is at the back of the engine closest to the firewall.