If you noticed that the modern LS and the classic Small-Block are similar in size, you’re right – they are. During the development phase of the LS engine, engineers prioritized its dimensions to ensure compatibility with the previous Gen 2 small block Chevy. They aimed for a compact design, similar to its predecessor, making it a suitable replacement.
Comparing heights, many LS versions align closely with the old models, though some truck variants stand taller. The length typically matches at 30 inches, though some variations come close at 29.50 inches. In terms of width, the LS engine is notably slimmer, approximately two inches narrower than its predecessor. This streamlined design has contributed to the widespread popularity of LS swaps in classic GM vehicles initially powered by a small block Chevy, requiring minimal adjustments beyond engine mounts and adapters.