Hi Andy,
thanks for your help it has been very useful, when double checking all the dimensions again as you suggested,i realized i was measuring to the top edge of SB4 not SB3 no wonder i was so far out!
The distance measured is 829 for TT7,so everythings ok!
I suppose having not worked on the chassis for a while i got a bit confused and panicked that i had gone very wrong.
So thanks again for your sound advice.
Dave.
