That series of Chevy inline sixes began production as a 194 cubic inch in the Chevy II compact cars, around 1962 or 63, I believe. The displacement went up to 230, and then 250. The 292 is a "raised block" variant that was used in medium duty trucks. All the engines have 7 main bearings and thinwall castings for weight reduction, and they share the same bellhousing bolt pattern as Chevy V8's. A lot of internal parts are shared with V8 engines, or at least they have a similar design, such as stamped steel rocker arms on individual studs and ball pivots. 307 V8 flat top pistons are a drop-in fit in a 250, replacing the dish top types to get a little compression boost. High mileage 250's have a tendency to wear the #1 cylinder more than the others, sometimes requiring that one to be sleeved on a rebuild instead of boring the whole engine to a large oversize.
Jerry
