To rebuild or not rebuild, that's the question!

[markjohnson]

Most of the #289 blocks I've come across are two bolts, but I've pulled the pan and it is a factory four bolt main, steel crank, 7/16 rod engine. Even the heads are 1972 #291's with the #569 aluminum pancake intake manifold. The camshaft is even stamped the correct number as a stock LS-6 camshaft. I would almost bet that tirebird's LS-6 is also a #289 block. Like I said, I've seen a few of these 1972 LS-6's and can only conclude that Tonowanda ran a batch of these for whatever reason. The normal LS-6 crate engine that everyone knows came with rectangular port/open chamber heads and lower compression. By the way, this has ran 11.80@112 with headers,through the mufflers, on BFG drag radials.