what grade & length are intake manifold to valve body bolts?

**CraigR** · 05-27-2015, 08:07 PM

I need to replace the bolts for the intake manifold to valve body. I need to know what grade 5 or 8,and the 2 different lengths. This I for a 248 I-8. Where can I find this info in the future ? Thanks, CraigR

**Bob** · 05-27-2015, 08:59 PM

I am uncertain exactly which bolts you refer to, but I don't believe they will be critical. A grade 5 will be adequate. A good rule of thumb is the distance they should extend into a threaded hole should be the diameter of the bolt plus two threads. A 3/8" bolt with a 9/16" wrench size should go into the hole 3/8" plus two threads.

**CraigR** · 05-27-2015, 09:28 PM

Originally Posted by Bob

I am uncertain exactly which bolts you refer to, but I don't believe they will be critical. A grade 5 will be adequate. A good rule of thumb is the distance they should extend into a threaded hole should be the diameter of the bolt plus two threads. A 3/8" bolt with a 9/16" wrench size should go into the hole 3/8" plus two threads.

Thanks for the response, Bob. The valve body is the section that has the heat riser butterfly. I have a 1951 wholesale p parts guide that Buick put out, it has a picture of all components with part numbers. It doesn't give a description of the part though! LOL Thanks CraigR