Flushing Cooling system & Thermostat

[<NickArg@domain.elided>]

I'm currently flushing the radiator & block out, but cannot seem
to find a drain tab on the block. The ROM suggests than this
was not present on Mark II's. Is this correct? Apart from sticking
a hosepipe in the thermostat housing and bottom hose
any other suggestions? - apart from taking the heads off :-)

I've removed the existing thermostat and found it to be the incorrect
type e.g without the blanking disk. Hopefully this may be the source of
the overheating in traffic. (great web site with pics at
www.vtr.org/maintain/stag-cooling/htlm) showing the different types
I've got a correct 82 degree one from the previous owner. Will this do 
or should I get an 88 degree one as the ROM suggests?

Regards


Nick
76 Mk II