horsepower numbers could be similar but advantage big block with its bigger heads (ie, chambers and runner dimensions) . it will make more torque to by the same reasoning. i believe i seen comparo’s like that… they might be able to hang with hp numbers but never match the big blocks torque curves. and its hard to get a small block head to flow like big bigblock heads… some of those bigblock heads flow 350-380cfm…i never seen a small block 23 degree head flow more than 330 or so. AFR’s best right now i think is 320.
not bad but the one problem i see with GM’s 383’s is that they use a 3.80 inch stroke…forged crank so its strong but it also costs near 1100 bucks… thats why that crate motor is so expensive. it has extra 1000 bucks in a crank that you dont need. you can get a forged crank for 600-700 bucks that will handle as much power, and use common sized pistons and rods designed for a 3.75 inch stroke instead of the 3.80. but the motor doesnt have forged rods or pistons…so those will go way before the crank ever does. i always hear ppl breakin rods/pistons but never cranks…even on cast cranks. they should knock off 500-700 bucks off that crate motor.