I need some help here in choosing which route I want to go as I am needing 20+mpg on average for everyday driving.

I can either go with a 383 or a 355. I really think the 355 will give me enough power for what I want (daily driver with some power) but the 383 has been recommended more than once to me to do instead of going with the eventual procharger I was planning. I am at the point where all I need is a crank to go one way or another. Here is the build up:

Super Ram (base, runners, plenum, 52mm throttle body)
TRW fordged pistons
Old school forged pink rods
8113 Corvette heads - Worked over pretty well.
LT4 Hot cam kit (rockers, springs, the works)
AFPR
3.23 posi rear end
well built 700R4
Walbro fuel pump
Hooker shorty 2055's
Carsound high flow cat
Custom catback

What will the horsepower and mpg difference be between a 383 and a 355 with the above combo.

Thanks guys.

James

 

I can't say for the 383, but the 355 with those parts will likely give you 20mpg and decent power if it's tuned well. 383 would be nice though. What is your plan for burning a new chip?

 

Buddy building the motor I believe has an Accell DFI tuner??? I remember going there and his laptop was all setup for it.

I have a convertible so it will never see the track, just slightly modded LS1 territory would be nice, but stock LS1 is just fine by me.

How much power would that 355 see?

Anyone with a 383 or 355 have any ideas?

 

I've seen lots of 350 super ram cars with similar cams making well over over 300rwhp. Should be faster than all the stock LS1 fbodies you meet. For the 383, I'd just guess well over 330rwhp instead of well over 300

 

I was expecting better results than that Of course well over can mean many things

I am also going with a LS1 driveshaft, hoping that shaves a bit of the drivetrain loss and gives me some higher speeds.

So right now we are looking at the following

355 - 300+ RWHP - 20mpg average
383 - 330+ RWHP - ?mpg average

Any ideas with the 383?

 

Well, 330rwhp is alot more flywheel hp... 330hp+1/3 more (drivetrain loss) and you have around 440fwhp.

 

if you keep your foot out of the throttle, and able to bring the rpms down to less than 2000 rpms, i betcha you could get 20+ mpg out of a 383

 

Would I see that much loss with a full suspension upgrade, aluminum drive shaft (was thinking of going carbon fiber but cost is limiting that right now), built tranny and converter? I was hoping to lesson my loss to around 17-22%

That much HP equates to what kind of mpg? Going with the 383 that is? Also do I have any hope of getting the wheels to actually stick. I live in HB, California and it is COP central. They love to give tickets for showing excessive speed, which I don't need to be showing each time I hit the gas

 

Hey Ace that seems way too mild. 2,000 RPM? Now maybe this is just coming from someone driving a tired 305, but 2000-4000RPM is where I live (did I mention I idle at 1250, darn vacuum leak)

I can live with 15 in the city as long as I get 22+ on the highway in 4th gear.

383 tuned for mileage give this to me, while still delivering 300+hp to the wheels?