The V8 Owners Forum -

I have found the sizes from Rimmer. For anyone else interested, there is a metric size and a UNF size

7/16" by 1 1/8" UNF

M12 X 30 mm

Thanks for your help.

Thanks.

It has the distributor on it, and is the same physical size as the old one that was in the old engine no. 36D xxxxx. Do you happen to know the metric and imperial sizes of the two bolts?

I am putting in a new camshaft and cannot tell which bolt size and thread it should be.

The old bolt does not seem to fit. I think there is a metric and imperial size. Any ideas on what these sizes are?

Any help appreciated.

Thanks for all the answers, it appears a bit more flexible than I thought. Anything from 20 to 40 thou. So 30 thou it is. I'll let you know when I have it up and running.

OK, I think I will go with 30 thou, as a small increase in compression will not hurt, and will give a better performance - even if slight.

The reason for going with composite is that there are clear signs of head gasket leak out at the ends of both heads. Thanks for the replies.

I was going with 20 thou, would 30 thou increase the compression ratio much?

I am replacing the tin gasket with a thick gasket. How much should I get skimmed off to keep the compression standard (9.25:1) ?

The engine is a 3.9 l Range Rover (1990) vintage.

Thanks.