Just came back from the shop were we Dyno'd my Motor build by Best Machine. This is a 4.31 Bore 4.3 Stroke Naturally aspirated Big Block Buick Motor made 1004 HP with a bad crank main seal. We lost the seal after warm up and vacuum fell from -25, to below -10 due to the leak. Would like to Thank John Zerucha for loaning me his headers to make this test run possible. I Think with this I will Soon be able to update my Signature Line.