For the Chevrolet, cubic inch size is not the determining factor. The 'small block' is the casting design that was formally introduced in 1955 as the 265 cid; cubic inches range from 262 (one year only 1975) to 400 from the factory using various combinations of bore and stroke. The 'big block' was formally introduced in 1965 with 396cid and has since grown to 572cid from Chevrolet. There was also a 366cid 'big block' design used in trucks. The blocks, heads, etc. all completely different between the two engines, only the distributors happen to interchange (for the most part). The 'small block' has gone through some design changes such as the LS1 in 1997 that shares almost nothing with the traditional 'small block'. The 348/409/427 used from '58 to February '65 is sometimes referred to as a 'big block' since its design is different from the 'small block' of the era and was used before the introduction of the 396.
On the other hand, take Pontiac for example, the 'small block' 326 and 'big block' 389 are pretty much the same block and design - major difference is cubic inch displacement. For the Pontiac 'small block' and 'big block' are really a misnomer unless you're considering ONLY cubic inch size and not physical differences in the two. A "short block" normally refers to just the block, crank, rods, pistons (& rings), rod & main bearings, and usually camshaft and timing gears. A "long block" normally is a "short block" plus complete heads (valves, springs, retainers, etc.), lifters and pushrods. A "long block" might also include oil pump, oil pickup, and oil pan. "Turn-key" engines normally include everything needed to set the engine in your car, wire it up, add fluids, turn the key and drive off. Dale McIntosh 67 El Camino 1966/67 Chevelle Reference CD! http://www.chevellecd.com ACES #1709/TC Gold #92 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Peter Hnat Sent: Monday, June 26, 2006 11:01 AM To: [email protected] Subject: [Chevelle-list] Big block vs. Small block Would like to know the difference between a small block and a big block motor. I always thought a small block was anything 350 cu.in. and under, but recently have heard a 400 referred to as a small block . Also would like to know the difference between a "short block" and a "long block" . Thanks , Pete Hnat ' 69 Chevelle SS
