I have to say that I just found this thread and I hear people arguing over 383 and 400. I feel the 383 is a better choice for the street, where the 400/406/409 is better suited for the strip, it is not the most friendly engine in the cooling on the street. Both engines depending on how they are built can out perform the other, when you take in account what kind of car you have. I have had numerous 400 blocks and have had "HOT" problems, not overheating just a little warmer than people like on the street. I have actually down sized to a 355 that is built massive, best of everything, AND NO FUNNY GAS (NOS) Turbo 350, in a 64 impala with 28x9" rear tires, which is like lauching a house. It has run consistant mid 10s and I have smoked plenty of big blocks, 383's and 406's so argue if you must. I think its funny when big cube boys see that THERES A MOUSE IN THE HOUSE!!!!!!!!