All Oldsmobile Engine Bolt Sizes, Thread and Torque Specifications in one place
Oldsmobile enthusiast know the difficulty of finding quality information about their engines. GM didn't do us Oldsmobile fans any favours, as most shows and material produced was focused on Chevrolet and Pontiac products.
When you're in the middle of a big build, one of the more difficult things is finding a reliable source for information when you need it. I've ran into this a few times lately, and after scouring forums and trying to piece it together, it's still wrong most of the time.
John Herald Jr. is a legend in the Oldsmobile community. He's been building Oldsmobile Engines and rebuilding Rochester Quadrajets for as long as I've been interested in Oldsmobiles. With a lack of produced information out there, he produced this handy sheet that everyone should print and put on their toolbox.
All of this hardware can be found at most hardware stores. Head Bolts, Main Cap Bolts and Rod Bolts are left out as they should be purchased through ARP or through a dealer.
| Bolt Type | Size* | Torque Spec** | Notes |
| Balancer to crank | 3/4-16 x 1 1/2 | 160 ft/lbs | Grade 8 (Large Washer) |
| Balancer pulley | 5/16-18 x 3/4 | 20 ft/lbs | Grade 5 |
| Choke Tube to manifold | 5/16-18 x 5/8 | 15 ft/lbs | Grade 5 |
| Distributor hold down | 3/8-16 X 1 1/2 | 17 ft/lbs | Grade 5 |
| EGR Valve to intake | 5/16-18 x 7/8 | Grade 5 Flanged | |
| EGR Valve to intake | 3/8-16 x 7/8 | Grade 5 Flanged | |
| Exhaust manifold (to head) | 3/8-16 x 1 1/4 | 25 ft/lbs | Washer or Flanged G5 |
| Exhaust manifold flange thread | 3/8-16 | Grade 5 | |
| Flywheel (Automatic) | 7/16-20 x 1/2 | 60 ft/lbs | Grade 8 |
| Flywheel (Manual) | 7/16-20 x 1 | 90 ft/lbs | Grade 8 |
| Fuel pump jam nut (to block stud) | 5/16-24 | 25 ft/lbs | Washer |
| Fuel pump lower bolt | 5/16-18 x 1 | 25 ft/lbs | Washer or flangedG5 |
| Fuel pump stud to block | 5/16-18 x 5/16 24 | 25 ft/lbs | Grade 5 |
| Intake manifold long bolt | 3/8-16 x 2 | 35 ft/lbs | Washer/Pattern G5 |
| Intake manifold short bolt | 3/8-16 x 1 1/4 | 35 ft/lbs | Washer/Pattern G5 |
| Motor mount (to block) | 7/16-14 x 1 | 80 ft/lbs | Washer |
| Oil filter housing short bolts x2 | 3/8-16 x 1 | 35 ft/lbs | Grade 5 |
| Oil Filter housing long bolt | 3/8-16 x 1 1/8 | 35 ft/lbs | Grade 5 |
| Oil pump short bolt (to main cap) | 3/8-16 x 1 1/8 | 35 ft/lbs | Lock Washer Grade 8 |
| Oil pump long bolt (to main cap) | 3/8-16 x 1 3/4 | 35 ft/lbs | Lock Washer Grade 8 |
| Oil Pan (corners) | 5/16-18 x 1/2 | 7 ft/lbs | Washer or Flanged |
| Oil Pan (rails) | 1/4-20 x 1/2 | 7 ft/lbs | Grade 5 Flanged |
| Rocker arm | 5/16-18 x 1 3/8 | 25 ft/lbs | Grade 5 Flanged |
| Thermostat housing | 5/16-18 x 1 1/4 | 20 ft/lbs | Grade 5 |
| Timing chain cover (lower) | 3/8-16 x 3/4 | 35 ft/lbs | Grade 5 Flanged |
| Valve cover | 1/4-20 x 1/2 | 7 ft lbs | Grade 5 Flanged |
| Water Pump to cover (4 ea) | 1/4-20 x 1 1/4 | 13 ft/lbs | Grade 5 |
| Water pump short | 5/16-18 x 1 1/4 | 13 ft/lbs | Grade 5 |
| Water pump long | 5/16-18 x 2 1/2 | 13 ft/lbs | Grade 5 |
| Water pump stud (in pump) | 5/16-24 | Stud is approx 1" total | |
| Water pump fan nut | 5/16-18 | ||
| 455 valley tray | 1/4-20 x 1/2 | Grade 5 | |
Thank you to John Herald Jr for compiling this list and submitting it to Pacific GBody Co! If you're looking for a rebuild on your Rochester Quadrajet, shoot him a message on Facebook.
