Lamda head gaskets from Dobson Gaskets (
www.dobsongasket.com) 01535 607257
Ring up and talk to David (or, perhaps, Andrew)
The basic gasket is known as "Lambda type 78" (SV7451) This is laser cut from the original engineering drawings of the cylinder head and corresponds to the standard VIIth series bore of 77.3mm. It is made from compressed graphite with a copper fire ring and should fit all VIIth series cars which have not been bored out too much.
If your bore is substantially more than 77.3mm you are into type 79 territory. Type 79 standard bore is 82.55 but mine is much bigger! You need to ask to be sent a template which is cut from 3mm pseudo-asbestos and offer it up to the block locating it by the vertical drive tunnel ring and the locating ring at the back of the block. Carefully cut round the bores with a sharp knife held vertically against the cylinder walls and send it back
identified by the car's registration number. This will be fed into the laser cutter via the CAD and will then be kept for future reference so if you need more gaskets quote "type 79 reg. XX1111" and they will know what to do.
