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+--- Thread: Crank pulley bolt (/showthread.php?tid=16)
Crank pulley bolt - Mur1234 - 02-05-2026
Hey everyone,
I have an '87 Ciera 2.8 MPFI. I might attempt to replace the crank balancer. Does anyone know the crank bolt size? Or a part number from GM, Dorman, etc. I googled it and apparently there's a common bolt for sale for the Chevy 305, 350 that fits the 2.8/3.1 multi port.
7/16" - 20 pitch.
2 1/2" length.
5/8" hex head.
Grade 8 threads.
Can anyone confirm this?
I'd just match the bolt when I take it out. I'm a bit intimidated with removing balancer lol. I'd just like to find bolt before I even start.
Thanks
RE: Crank pulley bolt - 73blazer - 02-09-2026
I can probably find a GM number for you in my GM A-Body parts book when I return later this week, but like you kinda eluded to, I don't think there is anything particularly special about it. Matching it from the local hardware store should be sufficient!
BTW. Welcome!
RE: Crank pulley bolt - Mur1234 - 02-09-2026
Thanks!
Yeah it took a few hours but I found outdated part numbers. Dorman or ATP don't have a direct fit.
Seems odd it's the same bolt for the 2.8, 3.1, 3.4, 3.5, 3.9 from '87 to 2011. CLEARLY no need for aftermarket support.