[Sirrotica]

As Cliff has said, the ridge is a great indicator on cylinder wear. Pontiac blocks stand up well to wear, if they were taken care of.

I have re ringed a lot of 400s 428s and 455s and run them at stock bore with the cast pistons they came with. I still own a standard bore, low mileage 428 that I ran in the 69 Grand Prix race car in my third signature pic, it has TRW forged pistons in it, still ran fine when removed from the race car after 3 seasons.

When I was racing dirt track cars we had a claimer rule on the beginner class cars of $225, meaning a competitor could buy your car if you won 3 races in a row (1975 thru 1982 time period). Obviously with the rule you didn't want to infuse a ton of money into the car, or engine, so I did a lot of engines with just a hone, new rings and bearings, good oil pump and a 068 cam and new lifters, and a fresh valve job, although if the valve seal was good, sometimes not even a valve job.

I did engines for myself, as well as people I sponsored having owned a business at the time. So I did a good deal on Pontiacs with standard bores, stock pistons, and rods. They survived very well in that environment, and as my signature pictures show, I did quite well in my racing career.

When I retired the car in the second picture the engine was sold, and went into a 68 Firebird street car. That engine had 2 full seasons of racing on it. Years later I happened to run into the guy, and he still had the car, but had taken it off the road due to rust issues. He said the engine still ran well, and was looking for another car to put it in. That answers the longevity question.

The engines I built won a lot of races over the time they were in race cars. These engines had acceptable blow by, didn't use oil, and had good power. Overheating them repeatedly though, would ruin the ring seal quickly. Maybe my experience with re ringing a standard bore Pontiac will hopefully give you some insight.