Will A Few Of These Modifications Get A Few MPG Gain Out Of A 1983 C20 Suburban 454 Carb TH400 Duall

[WarWagon]

Why not start with a non-runner? Then drop in a project engine. No reason to turn a runner into a never ending project thats down for months.

Modern crew cab stuff gets MPG. 18 for 1/2 tons...

Seriously enjoy what you have now. Some of the MPG stuff costs more to buy and in upkeep. I regret dad sold our 94 burb with the 454 as the Olds Bravada V6 that replaced it was a lemon.

My diesel eats parts and till modified got same MPG as a 454. Buddy has a 1993 454 pickup like mine. I have $12,000 or more in diesel engines, trans, turbo. He has $2,000 in it shy of a $800 needed front end. He is always out of fuel in it. After mods unloaded his stock 454 feels about the same as my 6.5. My 5.9 will stomp both towing, but, add serious cash to buy and mod the 5.9 Cummins.

Live with the 454's bullet-proof love of fuel or get a econobox. Got to make the best of the engines howl while watching the gas guage move.

We may buy the diesel for better MPG, but, there are 40+MPG rigs out there that they bury you in if you wreck. Yeah, I didn't buy these for the MPG. Suggest same attitude for you.

 

[THEFERMANATOR]

Don't waste your money on the stand alone wiring harness kits like painless and the like. For $400 or less there is literally DOZENS of places that will take a stock uncut GM harness and make it stand alone for you. Or there is websites like lt1swap that literally have the step by step directions to build your own stand alone harness. As to reliability, I'll stack an 0411 PCM up against a GM HEI any day of the week. It is not uncommon for the average shade tree guy to do an LS swap in a weekend now if you plan your swap out. There have been so many done in so many vehicles, you would be hard pressed to NOT find all the details needed on the internet and how to overcome any obstacles. You have drop in engi,e mounts on sliders, wiring harnesses that only require a ground, battery feed, and a switched source, fuel pumps and filters with regulators built in that mount inline, guages are of no issue as they can ge setup to a multitude of outputs, adapters to install aftermarket guages, and many factory GM options, and on and on and on. Squarebody with an LS swap has been done hundreds of times now with websites dedicated to selling vehicle specific swap parts.

As to which engine, the 4.8 and 5.3l stock will fall well short of a 454. Even the 6.0l is going to feel lacking until you get the rpm's up. As to engine combos, the 8.1l 4l85e only came in the suburban and avalanche, it never made it into a van that I'm aware of. The 6.0l 4l80e combo came in so many different vehicles it's ridiculous. You can even find the 6.0l in half ton platforms, but beware they came backed with the 4l65e trans, and it did not have a great track record holdi,g up to the 6.0l's torque.

You have lots of options out there to improve your power and mpg's, but dumping money into a 454 would not be a wise finacial decision in my opinion.

 

[Tillard]

Why not start with a non-runner? Then drop in a project engine. No reason to turn a runner into a never ending project thats down for months.

Modern crew cab stuff gets MPG. 18 for 1/2 tons...

Seriously enjoy what you have now. Some of the MPG stuff costs more to buy and in upkeep. I regret dad sold our 94 burb with the 454 as the Olds Bravada V6 that replaced it was a lemon.

My diesel eats parts and till modified got same MPG as a 454. Buddy has a 1993 454 pickup like mine. I have $12,000 or more in diesel engines, trans, turbo. He has $2,000 in it shy of a $800 needed front end. He is always out of fuel in it. After mods unloaded his stock 454 feels about the same as my 6.5. My 5.9 will stomp both towing, but, add serious cash to buy and mod the 5.9 Cummins.

Live with the 454's bullet-proof love of fuel or get a econobox. Got to make the best of the engines howl while watching the gas guage move.

We may buy the diesel for better MPG, but, there are 40+MPG rigs out there that they bury you in if you wreck. Yeah, I didn't buy these for the MPG. Suggest same attitude for you.

like you said before about having a smaller vehicle . I got a 1999 Crown Victoria LX. not "small" but decent fuel mileage with its reliable 4.6 V8. it things get heavy out comes the suburban

 

[WarWagon]

like you said before about having a smaller vehicle . I got a 1999 Crown Victoria LX. not "small" but decent fuel mileage with its reliable 4.6 V8. it things get heavy out comes the suburban

I like your vehicle choices! That is a good looking rig.

 

[Tillard]

I like your vehicle choices! That is a good looking rig.

Thanx . it gets me where I got to go. I wonder instead of dumping funds into the motor and/transmission, first iIhave to get a 2 inch lift to have some grounds clearance especially with the rough streets and some flooding that happens once a while here New Orleans.

Then the paint such as having the rims painted black and vehicle for green(wonder which is the right paint out there the military uses?

 

[Tillard]

I like your vehicle choices! That is a good looking rig.

thanx for liking my vehicle choices, as for the crown Victoria i got cause the motor is the same as a mustang , along with being a full size sedan with decent fuel mileage, reliable and not get pulled over by law enforcement Thanx to to these Vehicles still being used as patrol vehicles(the NOPD, Louisiana State Police and Sheriffs Office still has half or some out here in the fleet on the streets)