I had a '76 Pontiac Grand Prix with the 400 V8, which I guess is 'one of the larger V8s'. It virtually never broke - I honestly don't remember ever having to repair it.
I actually disliked the car because it had vinyl seats, but I'd have to say it was one of the most reliable cars I've ever owned. Really I doubt there was much difference in terms of reliability between the various 350s and the other GM V8s of the 1970s - all were bulletproof and amazingly durable.
I find the first comment here to be true... I had a 1976 Bonneville coupe, and they are much more rare than the Catalinas. The Grand Ville was not made in 1976.
The reason that the 400 v8 was durable (in my opinion) is because it had a bigger bore than stroke. It didn't tear itself up, with the pistons flying up and down and tearing up the main bearings.
I had mine for nine years, and the engine and transmission never had a problem. The car weighed 4700 lbs.
In high school in the late 1980s, I had a '76 Grand Prix with the 400, and my friend had a '77 with the 301. In both cases the cars never broke - seriously they were the most reliable cars I've ever seen, and I've had some very reliable old Detroit iron - and each lasted in the 250,000-300,000 miles range.
For some reason I liked my friend's 301 better - I guess it was a base model, and though it had less power, it was very smooth and soft-riding. Mine was a bit more 'sporty' model, probably lower rear-end gearing, and slightly bumpier ride.
The late 1960-mid 1980's Oldsmobile small blocks were the most durable in my opinion. They only had a 3.385" stroke, and still delivered excellent torque for their era. The 260 (4.3) was pretty underpowered, but there is someone around here with a 1980 Cutlass with 450,000+ original miles still chugging around every day. The 307, 350, and 403 were also excellent motors for their time.
"The 260 (4.3) was pretty underpowered"
- To the point where it wasn't even turning up as much HP as Oldsmobile's original 303 Rocket V8 of 1949!