How rare is the 1976 Chevy 400 Ci engine?

Answer 1

Rare? Hmmm. rare is a relative term. The 400 was the largest version of the "generation 1" smallblock as it has now come to be called since there came to be a new generation redesign of the smallblock. The 350 was stroked from 3.48 to 3.75 inches and bore was increased from 4 inches to 4.125 but in order to increase the bore GM had to "Siamese" the cylinder walls so that coolant could no longer pass between. Uneven cooling and uneven metal around the cylinders was not the greatest thing for big HP engines. The 400 was designed as a torquey but light (relatively) engine for the heavy GM cars and trucks of the 70s. A great engine and fun to build up mildly, but best used for low rpm power due to the shorter rods/longer stroke. Deck height was not altered, nothing external was altered other than external type balancing (unbalanced flywheel and damper). Most HP versions use the non-siamesed block, which is the 4 inch bore and the 3.75 crank to get the beloved 383 "stroker" engine. Putting the 350 crank in the 400 block makes an interesting 370 inch (give or take) HP engine but you still are left with the siamesed bore. Then again, this does add stiffness to the block perhaps. Back to rarity, figure it was made in large numbers from around 1970 to 1976.