Ed, Horsepower is somewhat subjective - Engine A may make more HP than identically prepared engine B, and a different set of weather or tuning varibles might have engine B making more HP than engine A. NHRA routinely "factored" engine horsepowers over the years, in some cases where the automaker may have claimed a lower horsepower to gain a competitive advantage (like the 426 Hemi). In other cases it is purported that engines were factored to either A) "level" the playing field, or B) cater to a bunch of whiners who didn't like a (Mopar) car "bombing" their class record or index. Many examples were given at the factory drag seminars and published in the old DC bibles of Mopar engines being factored way up (sometimes resulting in a car having to compete 3-4 classes higher than it should). NHRA factors gave some indication where a manufacturer had either over-rated the engine to sell cars, or under-rated the engine to win races (win on Sunday, sell on Monday). The '64-65 Race Hemi was generally under-rated at 425 HP and was factored to 500HP. Conversely, the late 60's 383's were often de-rated from their advertised 330/335HP to around 300HP. Again, not iron-clad, but an indication. It should be mentioned that HP back then was rated at "Gross HP", which was the engine on a stand, with no accessories (PS pump, fan, alternator, exhaust), and under ideal conditions. In the early 70's engines were rated at a variety of lower numbers, in some cases to appease the insurance companies and in others to appease the government. "Net" horsepower was rated with all accessories, in the car, at a pre-determined (levelled) set of less than ideal conditions. Lately everybody talks "rear wheel" horsepower, which takes into account things like parasitic drag in the driveline and accessories, etc. It is easily measured on an engine dyno, but doesn't relate well to discussions of engine horsepower. So to answer your question, NHRA appears to have pretty much left the Max Wedges alone, sometimes tinkering by 5-10HP to cater to the aforementioned whiny racers who didn't like their hot big block Chevies getting trailered in the first round by a homely Mopar sedan or station wagon. This would suggest that 410HP, in stock trim, as tested, was accurate or acceptably accurate at that time. Check it out here... http://www.nhra.net/tech_specs/classification/classfiles/1962PLY.xls Note that the 343HP 383 was de-rated where the 413's were not. Now once the cars left the dealerships and engines were blueprinted and modified to take maximum advantage of the rules, the gloves were off :) SC -----Original Message----- From: ed keaton [mailto:gtx69@xxxxxxx] Sent: Monday, December 07, 2009 9:25 PM To: 1962to1965mopars Subject: 413 max horses Anyone know what the true horsepower of the 62 413 11.1 comp engine was ? It was said to be 410 horsepower.I have heard it was more. [Non-text portions of this message have been removed] ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html. ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.