Stop! You're killing me!
Oil for completely stock 1973 Pontiac 400 with 100K+ miles.
- Thread starter JRHAWK9
- Start date
Chevy did have some soft cams around that time, Don't know if Pontiac had it too.
As far as I know it was just Chevy around 78-83. Oldsmobile and Pontiac didn't have that problem. I was just born in 83 but I started with all my automotive research back in the early 90s.
My friend did find spalling/pitting on the camshaft of both the 79 olds 350 (which he swapped with a mild lunati camshaft years ago) and his 72 351 Cleveland which he rebuilt completely but those weren't wear as much as damage from sitting for years with old oil in them and some moisture probably.
My 76 olds still has the original one in it so hopefully no spalling or wear.
My 1977 Malibu Classic 305 had one replaced in 1980.
What's interesting is that the conventional 10W-40s I've seen are more expensive in many instances than semi or full synthetics. Here are some Walmart and Amazon prices:
Last edited:
I had no idea 10w40 conventional was crazy expensive now. Just wow! I guess there's just no demand in the market for it anymore, so supply and demand dictates a much higher cost in single quarts especially.
It can still be found for a somewhat decent price in 5 qt jugs. BUT, if I were OP and I could get synthetic Xw40 cheaper, I'd run synthetic.I had no idea 10w40 conventional was crazy expensive now. Just wow! I guess there's just no demand in the market for it anymore, so supply and demand dictates a much higher cost in single quarts especially.
This.I vote 0-40
I should say 77. Seems like it might have been a build date split. I know someone who still drives a 77 impala his dad bought new with 350k miles on the original camshaft and I've heard of several others but also a couple that did fail.
My dad's 1979 cam failed around 17 years old and he drove it a few years that way on 7 cylinders and it just kept running.
Those 8:1 compression 400s were pretty low power for their displacement, for sure. The pre-1971 engines were less detuned. My first car was a 72 Catalina with the post-71 400. Used Castrol 10W-40 and changed it every 3K - it was the default OCI of the 80s. That engine was bulletproof. Sold the car in 1990 with 212,000 miles on it; original engine and transmission. It had numerous rusted out areas and various water leaks every time it rained. I replaced the points distributor with an HEI from a 75 Pontiac and replaced the 2 barrel Rochester carb with a four barrel Holly Q-Jet bolt on replacement. It actually improved the fuel economy to a whopping 16mpg on the highway.
I've heard Pontiac's were pretty reliable, just like Oldsmobiles. Buick not so much. Chevy it depends on the year if they had bad cams or crack prone heads.
Mine ran hot all the time in the summer. If I got stuck in traffic I sometimes had to turn off the AC. This was even after replacing the three-row radiator with a four-row and installing a flex fan. If I had kept the car, the next step was to install an electric fan on the condenser to work with the belt driven fan (like Mercedes of that vintage used to do).
Mine did at one point and I had to flush like 8 gallons of water through the cooling system with the machine at work and then it was okay....but after I tried to convert it back to clutch fan the shroud had to be cut it fit the bigger rad and nothing helped until I converted it back to dual electric fans and now it stays cool no problem.
351W Turbo car with aggressive hydraulic flat tappet grind and 400 lb of open spring pressure. Valvoline VR1 Full Synthetic 10W-30. No cam issues so far.
Similar threads
