given all factors are the same and i mean everything. how much more, will the few cubic inch differance, between a 396 vs a 383 produce horse power wise. i know it shouldnt be much ,just kind of wondering is the differance in cost to build a 396 worth it over a 383. oh if you want more factors to answer the last question. stock ecm tuned , no after market ecm. only going to spin to 6700 or so . Lt1 or aftermarket LT1 castings to be used (actually tfs from AI) also factory lt1 block with better 4 bolt main caps. sorry if some of this doesnt make sense i am on some GOOD cold meds lol screens blury a little

 

Theoretically, you'd only get about 3.4% more HP out of the 396. 3.4% is how much bigger a 396 is than the 383; therefore, you'd get 3.4% more gas to burn in the cylinders. That is only about 13 more HP over a 383 cu.in. engine producing 400 HP. Of course this is assuming a complete stoichiometeric (not lean or rich) air/fuel fill of the cylinders with a complete burn of the gas.

You could see more or less of a power gain... But... the old saying goes, "there is no replacement for displacement."

 

The advantage of an LT1 stroker motor is in the torque gained. Especially down in the lower RPMs where torque rules. Torque is what gets a vehicle moving which helps alot when the vehicle is relatively heavy. Given that, the general consensus has been that a 396 is pretty pricey to build to gain just 13 ci. over a 383.