JeremyNH
I'm Awesome
98 Z71 with a new 383 (390 technically - 3.8" stroke 0.040 over). It has AFR 190cc heads with a little more than 100 miles into break in. Runs perfect. Issue came up on final assembly two weeks ago that one of the accessory bracket bolts (AC bracket top outboard) started to pull out the aluminum threads on torqueing. It's not stripped as I stopped as soon as I saw the torque reduction, backed it out, used a longer bolt to chase the threads and re-installed without a torque wrench but could feel the threads grips are soft. Left it snug but not torqued. AFR 190s have accessory bolt and valve cover center bolt holes tapped short and they say in the install instructions to reduce the length by 1/3" to keep them from bottoming out which I did (1/4" about as 1/3" seemed too much). Obviously on retrospect the reduced thread contact wasn't going to allow for high torque (32 ft-lbs, not all that high but too high here). Went to the treasure yard and picked up four accessory bracket studs thinking I could bottom them out using the full pitch of the threaded holes and replaced the four bracket bolts with studs (two in the alternator bracket, two in the AC bracket). The offending bolt hole is still soft so I again left it snug but not torqued. My plan is to let it be for now and see what happens. Probably it will be fine and riskier to try to do something about it until I have evidence that I need to. My thought was to use JB Weld to permanently affix the stud in the head. The threads are present and the studs thread in and out just fine so epoxy them in to keep them from turning and continuing to damage the threads and let the remaining metal keep the stud from pulling out. If it's an issue in the future I can always just cut them off and swap the heads to use the still fresh holes now in the back. I have little experience with JB Weld but it seemed this may be a good application for it. Thoughts?