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Discussion Starter #1
ok so the 73 trans am engine that i have has 230 HP or more if Pontiac changed the compression by heads could i get 350 horse by changing the heads to 87cc Eldelbrock head , up the 650 carb to a 750 keep the intake maybe change the cam i dont know i dont want a crazy cam gas already sucks lol and if not how much hp can i expect to gain i know this is almost impossible to answer but i just figured i would ask just the same
 

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64-67 Expert
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With the heads, carb, and a decent cam (068 or comparable) you'd be in the 320-350 HP range. It would be a "bread and butter" totally drivable engine.
 

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67 Basket Case Restorer
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068 are the last three numbers of the factory part number for a particular cam. Any cam that has similar specs to a factory tripower or ram air cam will be good. One thing to remember about the hp rating on the 73 you have is that it's net, or flywheel as installed, hp for insurance purposes. The gross hp is still probably 275 or so.
My 73 Motors Manual shows the 73 cam specs as still very close to the earlier years for lift with a little less duration so the cam is close. Like Geeteeohguy said, the heads are probably going to give you a noticeable increase and a bigger carb will help too.
 

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One thing to remember about the hp rating on the 73 you have is that it's net, or flywheel as installed, hp for insurance purposes. The gross hp is still probably 275 or so.
My 73 Motors Manual shows the 73 cam specs as still very close to the earlier years for lift with a little less duration so the cam is close. Like Geeteeohguy said, the heads are probably going to give you a noticeable increase and a bigger carb will help too.
:agree

The BHP ratings prior to 71 were calculated on dynos using headers and without the loses from water pumps, alternators, power steering pumps and A/C compressors, after 71 the sae HP ratings were calculated as Mitch mentioned "as installed" and were lower for insurance requirements.

When I had my 66 389 motor rebuilt they dynoed it the old fashion way and I was able to get the BHP numbers you are looking for or what the factory stated prior to 71.
 
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