Well, as you can see, it is March and I did this repair in December, hard to remember the bolt length. I am guessing it was about 1/2" inch shorter is all. You can measure from the block to the water inlet housing(best of my memory) to get the length of the bolt.
best of luck,
Kevo

 

Mr.Vivona, email me directly here kevoz-at-verizon-dot-net

 

I successfully changed the Cam O-ring this past Saturday by using the "Cut the Bolt" method so I did not have to remove the complete Thermostat housing assembly. I also happened to have a metric bolt that when cut down slightly in length fit the application. I would also note in the procedure to maximize the acceptable bolt length is that you insert the bolt into the bolt hole of the plate before rotating the plate into final position for threading into the head. This gives you a slightly longer bolt length (Thickness of the plate) for maximum thread length.

This is a great fix for an irritating problem with minimal effort. The O-ring I replaced was baked and hard... I Expect this to be a regular maintenance item.

 

Diam2002-Thanks for the update. My Silicone RTV fix has held up over a year on both Diamantes, but should it start leaking again I will try the cut-bolt method and replace the o-ring. Your detailed information will be very helpful.

I did find that the distributor o-ring was also leaking and replaced it with one from the Autozone distributor o-ring kit, Item# 80024.

 

By the way, I didn't post the part number I used. Here it is to save time researching.

Camshaft O-Ring Ishino Camshaft O-Ring Diamante|LS Ishino Price: $ 2.95 Part #: W0133-1669283

Mr. Vivona, Thanks for identifying the distributor O-Ring part number.