V8 intake plenums use a T40 bolt (5/16"-18 x 1.25") in the center right position (passenger side - the photo was taken with the hood removed). Most bits are too large to fit, so either a long bit is required, or some of the casting can be ground away.
.
.
The other bolts are 5/16"-18 x 1.5" with 1/2" hex head, integral washer, and ~1/2" unthreaded shank. Some have a ~1/2-long stud on the head.
![v8plenumt40.jpg V8 intake plenums use a T40 bolt (5/16"-18 x 1.25") in the center right position (passenger side - the photo was taken with the hood removed). Most bits are too large to fit, so either a long bit is required, or some of the casting can be ground away.
[url=https://www.supermotors.net/registry/media/894688][img]https://www.supermotors.net/getfile/894688/thumbnail/intakev8efi.jpg[/img][/url] . [url=https://www.supermotors.net/registry/media/1048205][img]https://www.supermotors.net/getfile/1048205/thumbnail/plenumt40.jpg[/img][/url] . [url=https://www.supermotors.net/registry/media/1052886][img]https://www.supermotors.net/getfile/1052886/thumbnail/plenumt40j.jpg[/img][/url]
The other bolts are 5/16"-18 x 1.5" with 1/2" hex head, integral washer, and ~1/2" unthreaded shank. Some have a ~1/2-long stud on the head.](https://www.supermotors.net/getfile/1040058/fullsize/v8plenumt40.jpg)