Building an inline 6 Chevy 250 engine

The Chevy inline 17 is a design that has been around in one version or another since 1929 until 1990 in North American-market vehicles. During the fall of 1961, an unrelated and more modern version of the six was introduced (with the Chevy II) which has 7 main bearings and a short deck displacing 194 c.i.d. - the rear block face was redesigned with a bell-housing pattern which matched the Chevrolet V8's in production (both the small block and W-series) - transmission bell-housings for the V8 (both manual and automatic) were shared. The Chevy straight 6 250 c.i.d. engine was brought out in 1966. It has a 0.280" longer stroke (3.53") and the same bore (3.875") as the 230 c.i.d. straight 6. It boasts a 7 main bearing bottom end- quite an improvement over the previous generation inline's 4 main bearings. Although production ceased in 1990 for automotive use, the inline six (including its four cylinder variant still in production as the Vortec 3000 marine/industrial motor) was produced overseas in Latin America for Brazilian-market GM products until the 2001 model year. 250 production ended in 1984 (North America only) but the 292 tall deck engine remained in production in Mexico until 2001. Besides Latin America (e.g. Brasil, Argentina) where the six was locally manufactured, it was also manufactured by GM's Port Elizabeth, South Africa assembly plant until the company divested from South Africa in the mid-1980's during the Apartheid regime.