cam belt tensioner bolt

im about to change cambelt and fit the 16v tensioner to the 20v lump thats going in mine,
im aware ive to space it out 8mm, im pressuming oncs i do the original bolt will be too short

anybody got an idea of the bolt size and length required

thanks 

You can work out the length by adding the thickness of the tensioner + the thickness off the spacer and washer +15mm. I measured the depth of the bolt hole on my engine, was just shy of 20mm.

sorted mate, thatll do me, , wasnt sure how deep it went in, , as someones calling over to do the cambelt for me, didnt wanna have him come over and me not have a bolt ready

cheers mate