Do you feel comfortable like the stock when u drive it with 383? How many miles u get on your tank highway and in the city? What is your injector size?
Did you face any problems?

 

The engine's displacment does not determine how "comfortable" the engine feels when you drive it. That's determined mostly by the camshaft selection, and how well the PCM is tuned to handle that camshaft. Its very possible to put together a 383 or a 396 that is just as "streetable" as the 350ci engine that came with your car from the factory. Adding a few extra cubes just gives you the opportunity to make a bit more power and torque. If you use a mild cam, its going to drive just like a stocker, and give you almost the same fuel mileage as the stocker.

Where things start to happen is when you want to take maximum advantage of that extra displacment, and significantly increase torque and HP. Put a radical cam in there, and heads to support it, and you might end up with a setup that's not street friendly, and gets poor gas mileage. What is "streetable" is going to be different for each individual.

I think you can easilly see 450-500 flywheel HP with a well built 383, and keep it relatively street friendly. In some ways, the 383 (or any larger displacement) will actually accept a larger cam and still be easier to drive on the street.

My setup is selected to meet NJ rolling emissions. It was a daily driver for about 2 years, and really seemed not much different than the stock setup, at least regarding the ease of driving it on the street. It was close to 500 flywheel HP and was capable of producing better than 20mpg on the highway. Starts easy, doesn't sound a whole lot different than a stocker (wellll... the rattle of the solid roller lifters is always in the background ), and was very easy to drive. My approach was to keep it street friendly, and then be able to spray a 300-shot dry nitrous system for the track...... That requires the 78 #/HR injectors, and the aftermarket ECU that can drive those injectors over a broad range of operating conditions. But for a street friendly NA setup, that's not really necessary.

 

I have the luxury of no inspection so I could do with mine as I pleased.

I drive mine about 20 miles total a day, all accessories and A/C. When I first built the motor I used a smaller cam (the CC XE 224/230) It was very very very streetable, I actually called it "lame", But it ran low 12s at the track and knocked down 22 mpg on the highway (very thorough tune). I later upped the ante and switched to a GM847 cam (since everyone at the time was raving about it) It idles choppy and all my tuning efforts have not been able to completely remove the gassy smell, but it is still extremely driveable though town and stoplight to stoplight driving. It also knocked about 7 tenths off the 1/4 time.

If I had to redo mine I would go with a little more compression (running 10:1 now), and forged pistons, so I could run a big shot of nitrous at the track.

 

adding a higher gear ratio can help a bigger cam be more streetable since they have higher power peaks. if you have an M6 go with 4.10, or 3.73 with a decent stall on an A4.

 

What should be the max duration for a 383cid without sacrifice drivability?? I mean the end of the limits.

 

I built my motor to be a daily driver and it nearly as street freindly as my Hotcammed LT1. I get 27 MPG Hwy and 16-17 back and fourth to work (ome Hwy and 3/4 Stop and go city traffic) I have a 6 sped but I have a relitivly smooth idle (850-900 RPMs) and the car drives perfect untill you mash the gas