Specs, fluids & service · 1969–1972
Chevrolet K5 Blazer (1st generation) specs, fluids and service intervals
The numbers you need in the garage, on one page: spec sheet, capacities and service intervals, wheels and tires, and the parts to order. Sourced from owners, specialists and the factory; tags marked confirm in manual haven't been checked against a factory source yet.
Spec sheet
| MODEL YEARS | 1969–1972 (GMC Jimmy from 1970) |
|---|---|
| BASIS | Shortened 1969–72 K10 half-ton 4x4 |
| WHEELBASE | 104 in (2,642 mm) |
| LENGTH | 177.5 in (1969) · 180 in (1971) |
| WIDTH | 79 in |
| ENGINES | 250 I6 · 292 I6 (1970–71) · 307 V8 · 350 V8 |
| TRANSMISSIONS | 3-spd manual · SM465 4-spd · TH350 3-spd auto |
| TRANSFER CASE | Dana 20 (manual only) or NP205 |
| AXLES | Dana 44 front · GM 12-bolt semi-floating rear |
| BRAKES | Drums (1969–70) · power front discs (1971–72) |
| GROUND CLEARANCE | 8 in · 35° approach / 25° departure (1969) |
| FUEL TANK | 23.5 gal (1969 spec) · 21 gal (1971 spec) |
| MAX GVW | 5,000 lb |
| WHEEL BOLT PATTERN | 6 x 5.5 in |
By year
| YEARS | PLATFORM | ENGINE | OUTPUT | NOTES |
|---|---|---|---|---|
| 1969 | K5 Blazer (4x4 only) | 250 I6 · 307 V8 · 350 V8 | 110 / 135 / 170 net hp | Launch year. Four-wheel drums, top and passenger seat optional. 4,935 built. |
| 1970 | K5 Blazer · GMC Jimmy (new) | + 292 I6 | 292: 125 net hp | Two-wheel-drive Blazer and the GMC Jimmy arrive. New grille with six groups of 'dashes'. 11,527 built. |
| 1971 | K5 Blazer / Jimmy | 250 I6 · 292 I6 · 307 V8 · 350 V8 | 145 / — / 200 / 250 gross hp | Power front disc brakes standard. Egg-crate grille, 180 in length. 17,220 built. |
| 1972 | K5 Blazer / Jimmy | 250 I6 · 307 V8 · 350 V8 | 350: 175 net hp | 292 dropped. Grille surround no longer black. 44,266 built. |
| 1970–1972 | GMC Jimmy KE/KS-1550 | Same as Chevrolet | — | GMC grille and badging. 4,600–5,000 lb GVW on the 4x4s (1971 brochure). |
Fluids, capacities & service intervals
Assume a 50-year-old truck's fluids are any age and its rubber is original until proven otherwise. Baseline everything, then deal with the frame, steering and brakes before you trust it on a trail. Factory capacities for 1969–72 weren't available from sources we could verify, so check the Chevrolet shop manual for those.
| ITEM | SPEC / CAPACITY | INTERVAL | NOTES & PARTS |
|---|---|---|---|
| Engine oil & filter | Grade and capacity confirm in manual | Now, then every 3,000–5,000 mi confirm in manual | Check which engine you actually have: many trucks now run a later small-block or an LS.1971 Blazer oil filters by engine · RockAuto ↗ |
| Ignition: points or HEI, cap, rotor, plugs, wires | Points gap and timing confirm in manual | Now, then at every tune-up | Points ignition was original. Many owners convert to a GM HEI distributor, as on BaT's 1972 Highlander truck.1972 Blazer ignition parts · RockAuto ↗ |
| Coolant, hoses, radiator & thermostat | Coolant type and capacity confirm in manual | Flush now, then every 2 years | The 1969–72 option lists included heavy-duty cooling with air conditioning or an automatic. Upgraded aluminum radiators are common on restored trucks.1971 Blazer cooling system parts · RockAuto ↗ |
| Brake fluid, hoses & hardware | DOT 3 confirm in manual | Flush now, then every 2 years | 1969–70 trucks have four-wheel drums and 1971–72 trucks power front discs. Replace any rusty steel line rather than patching it.Stainless braided brake lines · Offroad Design ↗1971 Blazer brake parts · RockAuto ↗ |
| Transmission fluid | SM465 / 3-speed manual or TH350 automatic confirm in manual | Now | On a TH350, drop the pan and change the filter, then check for metal in the pan.1971 Blazer transmission parts · RockAuto ↗ |
| Transfer case oil | NP205: 80W-90 gear oil per CK5 members, filled to just below the fill hole · Dana 20 confirm in manual | Now | Identify the case first. The 205 is a one-piece iron case with a three-bolt idler cover on the back (Offroad Design).Remanufactured GM 6-bolt NP205 (if yours is beyond saving) · Offroad Design ↗ |
| Front (Dana 44) & rear (12-bolt) differential oil | Gear oil grade confirm in manual · friction modifier if Positraction | Now, and after any deep water | Check the axle tag and the SPID decal for the ratio (3.73 standard, 3.07 optional on V8 trucks) and for Positraction.12-bolt rear axle parts · Offroad Design ↗ |
| Front wheel bearings & spindle seals | Repack with wheel-bearing grease | Now, then after water crossings | Inspect the hubs while you're in there.GM Dana 44 / 10-bolt wheel bearing kit (per side) · Offroad Design ↗Spindle seal and bearing kit (per side) · Offroad Design ↗ |
| Driveshaft U-joints & slip yokes | Grease the serviceable joints | Every oil change | Any lift changes the driveshaft angles. Offroad Design has a tech page on driveshaft angles.1971 Blazer driveline parts · RockAuto ↗ |
| Spring & shackle bushings | Inspect for cracking and play | Now | Original rubber is usually finished. Greasable bolts help on a truck that sees water and mud.Universal 1969–1991 full vehicle bushing kit · Offroad Design ↗ |
| Steering box mount & linkage | Inspect the frame for cracks · check for play | Now | Straight-axle GM trucks are known for frame cracks at the box mount (Offroad Design).Bolt-in steering box brace, '67–72 GM 4WD · Offroad Design ↗ |
| Fuel filter, pump & tank | Inline filter · inspect the tank and sender | Filter now, then yearly | Trucks that have sat often need a new tank and sender, as several recent BaT sellers report.1971 Blazer fuel system parts · RockAuto ↗ |
| Top & door seals | Inspect and water-test | Now | Leaks rot floors. Reseal before you put down new carpet.Hardtop quarter-glass seal, 69–72 Blazer/Jimmy · Auto Metal Direct ↗ |
Capability
| Wheelbase | 104 in (2,642 mm) |
|---|---|
| Ground clearance | 8 in (203 mm) 1969 spec sheet |
| Approach / departure | 35° / 25° 1969 spec sheet |
| Fuel tank | 23.5 gal (89 L) 1969 spec sheet; the 1971 sheet lists 21 gal |
| Max GVW | 5,000 lb (2,268 kg) |
| Front axle capacity | 3,300 lb 1969 and 1971 spec sheets |
| Turning circle | 36.66 ft (11.2 m) curb to curb 1971 brochure, 4x4 |
| Curb weight | 3,875 lb (1,758 kg) Wikipedia, citing Popular Science (May 1969) |
Wheels & tires
| Factory tire | 7.35-15 (1969 standard) · E78-15B (1971 standard, 4x4) · Options to 10.00-16.5 (1969–71 spec sheets) |
|---|---|
| Bolt pattern | 6x139.7 (6x5.5") |
| Biggest tire · Stock | 33x12.50R15 |
| Biggest tire · 4 in | 35 in |
| Biggest tire · 5 in | 33 in |
Open the Chevrolet K5 Blazer (1st generation) in the tire fitment tool →
Common Chevrolet K5 Blazer (1st generation) repairs
- Brace the steering box mount before the frame cracksDIFFICULTY 2 / 5
- Reseal the hardtop, liftgate and doorsDIFFICULTY 2 / 5
- Cut out and replace rotten floors, rockers and wheelhousesDIFFICULTY 4 / 5
- Repack front wheel bearings and replace spindle sealsDIFFICULTY 3 / 5
- Replace worn locking hubsDIFFICULTY 2 / 5
- Rebush the leaf springs and shacklesDIFFICULTY 3 / 5
- Service the brakes (drums to 1970, front discs from 1971)DIFFICULTY 2 / 5
Always confirm torque figures, fluids and capacities against the factory service manual for your VIN. See the disclaimer; some parts links are affiliate links.