360 vs 383

273 said
Yes but a stock sbm weight is considered acceptable handling wise, so if a modded big block weighs similar to that should be acceptable also, now if building something like an auto cross car then the benefit of even less weight can be an advantage.

Right, which is what I was inferring about using aluminum parts. It really is probably a wash nowadays. Case in point - I have a 470" short block with a Scat ultralight 3.91" stroke crank in it that weighs around 54lbs. The finished bob weight is 2,222 grams which is over a POUND less than a stock 440. Think abut that! That's not a couple ounces, that's a pound which is a ton of weight. Topped with aluminum heads and intake etc., I'm in small block territory in regards to front to rear weight balance.

Also, the bigger bore can mean less weight, especially with a larger overbore. I'd be willing to bet a .060" over 383 weighs pretty close to a .030" over 360.

360 also has larger mains than the 318/340 so it requires larger bearings and creates more frictional area. I've read plenty about racers using 360 blocks with bearing spacers to use the 340 main bearing size.

A good question to discuss might be why in 1971-2 the factory engineers decided to drop the 383 in favor of the 400 and while turning it into a gas-guzzling pig (in stock form) or conversely, why was the 340 similarly replaced with a lower-performing but larger displacement engine?