1964 PONTIAC GTO

Typical onset: Original units often fail by 80,000-100,000 mi, but age is the bigger factor

Symptoms: Slipping between gears, especially 1st to 2nd, No forward engagement or delayed engagement when cold, Transmission overheating, burnt fluid smell, Harsh or banging shifts under throttle

Fix: Full rebuild of the Super Turbine 300 automatic. These two-speed units have limited parts availability and require specialized knowledge. Expect 12-16 hours labor for R&R and rebuild. Transmission cooler lines and cooler itself often need replacement simultaneously due to corrosion.

Estimated cost: $2,200-3,800

Typical onset: Varies widely; often appears 100,000+ mi or after years of sitting

Symptoms: Deep knocking sound from bottom end, especially under load, Low oil pressure at idle (below 10 psi hot), Metallic debris in oil filter or pan, Sudden catastrophic failure after overheating event

Fix: Main and rod bearing replacement requires complete disassembly. If the crank is scored, it needs grinding or replacement, adding significant cost. Original 389 blocks are valuable, so most owners opt for a full rebuild rather than replacement. Expect 30-40 hours for a proper rebuild including machining time, bearing replacement, and reassembly.

Estimated cost: $4,500-7,500

Symptoms: Rough idle, stumbling on acceleration, One or more carburetors flooding or leaking fuel, Poor fuel economy (sub-8 mpg) and black smoke, Hard starting when hot, Uneven throttle response, flat spots

Fix: The three Rochester two-barrel carbs require perfect synchronization and all vacuum lines intact. Rebuild kits for all three carbs plus progressive linkage adjustment. Most shops unfamiliar with Tri-Power setups will struggle. A knowledgeable tech needs 6-8 hours for complete rebuild and tuning.

Estimated cost: $800-1,400

Typical onset: 80,000-120,000 mi, or any age if the car sat for years

Symptoms: Blue smoke on startup and deceleration, Excessive oil consumption (quart every 500-800 miles), Low compression across multiple cylinders, Blowby visible at oil filler cap

Fix: Requires pulling the engine for proper re-ring job, honing cylinders, and replacing rings. If cylinders are tapered or out-of-round beyond spec, a full bore and oversize pistons are needed. Half-measures don't work on these engines. Plan for 25-35 hours including removal, machine work, and reinstallation.

Estimated cost: $3,500-5,500

Symptoms: Puddles of oil under engine after sitting, Oil-soaked undercarriage and frame rails, Low oil level requiring frequent top-ups, Oil on bellhousing from rear main seal

Fix: Rope-style rear main seals were standard in 1964 and notoriously leak with age. Replacement requires transmission removal. Front seal and oil pan gaskets also common culprits. Rear main alone is 8-10 hours; doing all seals and gaskets at once makes sense. Many owners upgrade to modern lip-style rear seal during the job.

Estimated cost: $900-1,600

Symptoms: Clunking when shifting into gear, Excessive drivetrain movement visible under throttle, Vibration at highway speeds, Transmission tail shaft sitting low, driveline angle off

Fix: Rubber transmission mount hardens and collapses over decades. Crossmember often rusts where it bolts to frame. Replacement is straightforward but requires supporting the transmission. 2-3 hours labor. Inspect motor mounts at the same time.

Estimated cost: $250-500