Intake Manifold Bolt Size and Recommendation...., I had one wiggle out before...what is the required size and style? Options

[second wind]

Hello all,
Thank you Sir Andy and Superhawk for getting my login working again. So I had a intake manifold bolt come out on the SLO WCR and my car was overheating big time. One of the guys took me to his shop with lift and he discovered the missing bolt. We found one that worked on his workbench but I had another 914 brother tell me there are special bolts for this application. Could someone please tell me the correct size and dimensions I need to replace the bolt correctly and is there a cure for it becoming loose again? That you all and Happy New Year to everyone.
All the best,
gg

[Superhawk996]

Looks like Pegasus has the prevailing torque flange nuts. This would let you ditch the useless lock washer and still get a good base to contact the manifold runner and have a prevailing torque nut.

The thing that will negate the effectiveness of this solution is that the stud will not be locked into the head as securely as this nut will be to the stud. It could still loosen at the head and the next time you need to remove it, you can virtually be guaranteed that the nut & stud will come out of the head as an assembly rather than just being able to remove the nut.

Here for consideration but personally I wouldn’t go this route.