max torque and fuel mileage from a 454

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silver97

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Building a 97 l29 454 for my suburban that has a nv4500, 3.73 gears and 31 inch tires. So I am looking for the best highway mileage and torque with this build. What recommendations do you guys have for cams, fuel injectors, machine work to the heads, tunes, and anything else.
 

Spastik Monkey

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Electric fans, headers, decent exhaust. These will never be a fuel efficient motor. Most of it will come from how you drive it.
 

silver97

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I am shooting for 15 mpg on the highway. I was planning on using Gibson headers with a aftermarket muffler. Also improvements in the airflow and fuel delivery. I was thinking of a good torque producing camshaft, 36lb injectors, and mild port work on the heads. Lastly, tuning the 411 pcm to optimize the efficiency of that setup.
 

Ironhead

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Nobody has stated the obvious here, and that is that folks do not generally buy a 454 engine for good gas mileage. This is an engine that is for doing heavy lifting, so to speak, and that means pumping a lot of mixture through those big cylinders.

Torque? for sure; gas mileage? not so much
 

Tech

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Owning my first BBC I'm asking the same questions. I'm looking at the parasitic loads first.
Fan, I'm thinking water pump adapter and a Duramax diesel electric clutch fan
Roller Rockers Crower Stainless. Low friction low heat free power. almost
Full windage tray, Get the oil away from the rotating assembly and put it back in the pan.
EGR enhancements, Filling those big holes with a little inert gas means that you are pumping less fresh air so you need less fuel. It can also let you put in more timing. I'm thinking about a mixer design built into a throttle body spacer.When you need the power it's turned off.
195 deg thermostat and a cold air intake, lower friction higher thermal efficiency longer engine life.
The Suburban already has a Banks intake and exhaust kit on it.
You can up the compression for some efficiency gains as well.
 

silver97

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Being that I am doing a full rebuild and haven't purchased any parts yet working with a engine tuners and machine shop's recommendations will be the key to my goal.
 
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Mangonesailor

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I am shooting for 15 mpg on the highway. I was planning on using Gibson headers with a aftermarket muffler. Also improvements in the airflow and fuel delivery. I was thinking of a good torque producing camshaft, 36lb injectors, and mild port work on the heads. Lastly, tuning the 411 pcm to optimize the efficiency of that setup.
Go Gibson headers, with 3" downpipes, to an H-pipe, to 2.75 or 3" all the way back. High-flow mufflers and no cats will go great with what you're doing.

Bankspowered98 on another forum claimed 430HP/667lb-ft with a .510/.540 cam, roller rockers, .30-over, compression bump (good idea), MSD box, CAI, larger throttle body (No clue where to get one), and full exhaust (full banks kit). He did not state if this was with a tune, but he had mentioned he was going to get another done for it. Later after the whipple he claimed 493/609. Odd numbers for 10lbs of boost and all of the rest of the work he did to it.

If it were me, and I was rebuilding the motor from the crank out, I would do just what he did. You'll probably need those 36lb injectors then.
 
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