Ok so the overheating is on hold now as when i was playing around today a new leak showed itself just under the thermostat housing between the manifold and the block, so its time for a new manifold.

Have checked out machining costs and have opted for new. Should i stick with the standard or go for something in the way of an edelbrok performer? i have been looking at different options and have noticed that on my standard one there are two hoses that run into the manifold just in front of the egr valve, one runs to the carby not sure about the other off hand. On some of the performance manifolds i have noticed this is not present, do they make edelbrocks and the like with these holes?

Thanks for any opinions and your help.

Agree.

I have what was known as the "Brock manifold" for sale if you are interested. It is a dual plane manifold, and in very good condition.
Genuine GMH manifold.

kc 308m is the part number used...a bit over 400 on the net...generally cheaper offline by more than 15%...do a search on the rare spares website as they are listed there and then ring american auto parts and see what there over the counter price is.....