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How And is It Possible To Convert A 1983 Chevy Suburban C20 Dually From 454 To 6.5 Diesel

Tillard

New Member
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6
Location
New Orleans, LA
Thread starter #1
There's a 1983 Suburban c20 with a Turbo400 transmission , Dually Converted , and with a 454 carb which I want to convert to a diesel 6.5 turbo or to a cummins.

is it alot to do and expensive? also is it worth it.


Or stick with the 454 thats Carbureted amd convert it to fuel injection and take off the original heads and put on the Vortec heads?

i don't drag race or go fast I drive the speed limit and tow medium heavy weight sometimes. like a 3 quarter ton vehicle on a trailer.
 

WarWagon

Well it hits on 7 of 8...
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AZ
#2
You can buy a tanker truck of hi-test gasoline for the cost to swap engines.

Then you have to find a good 6.5 that isn't cracked to death in the block or heads. Spend a grand on a good turbo as the GMx turbos are an asthma attack esp. when towing. Towing heavy a 6.5 with that small POS turbo gets 7.5 MPG where gas engines get 6 MPG: figuring fuel costs and higher diesel maintenance 2500, yes under 3000 miles, oil changes for this dirty engine frankly the 454 is a better option. A better high stall converter to match the big turbo is another $1,100.00. This is before you get a good Injection Pump and do the rest of the swap. Radiator and fuel system change come to mind.

In depth http://www.maxxtorque.com/2012/07/the-65l-diesel-factory-equipped-asthma.html

Cummins conversions may cost more, but, it's a rebuildable industrial engine where the 6.5 is a throw away engine. I have blown both up with a 5.9 lasting a whopping 500 miles after a rebuild. Towing heavy the MPG is better with a Cummins and HP/TQ is easily double what you can wring out of a 6.5. The 1983 frame can't take all you can get out of a hot-rod 5.9.

End of the day you are better off buying a diesel platform to start with and if reliability towing matters or puts $$ on the table consider a Medium Duty truck not a weak pickup or SUV that can't take the HD miles. Esp a 30+ year old rig that you have to build-rebuild before the word go.
 

Tillard

New Member
Messages
17
Likes
6
Location
New Orleans, LA
Thread starter #3
You can buy a tanker truck of hi-test gasoline for the cost to swap engines.

Then you have to find a good 6.5 that isn't cracked to death in the block or heads. Spend a grand on a good turbo as the GMx turbos are an asthma attack esp. when towing. Towing heavy a 6.5 with that small POS turbo gets 7.5 MPG where gas engines get 6 MPG: figuring fuel costs and higher diesel maintenance 2500, yes under 3000 miles, oil changes for this dirty engine frankly the 454 is a better option. A better high stall converter to match the big turbo is another $1,100.00. This is before you get a good Injection Pump and do the rest of the swap. Radiator and fuel system change come to mind.

In depth http://www.maxxtorque.com/2012/07/the-65l-diesel-factory-equipped-asthma.html

Cummins conversions may cost more, but, it's a rebuildable industrial engine where the 6.5 is a throw away engine. I have blown both up with a 5.9 lasting a whopping 500 miles after a rebuild. Towing heavy the MPG is better with a Cummins and HP/TQ is easily double what you can wring out of a 6.5. The 1983 frame can't take all you can get out of a hot-rod 5.9.

End of the day you are better off buying a diesel platform to start with and if reliability towing matters or puts $$ on the table consider a Medium Duty truck not a weak pickup or SUV that can't take the HD miles. Esp a 30+ year old rig that you have to build-rebuild before the word go.
in that case, I might go ahead and keep the 454 amd change out the original heads for vortec heads, and change to throttle body injection from Carburetted. which may help in fuel mileage if not alot along with performance. I already have on longtube headers
 

WarWagon

Well it hits on 7 of 8...
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Location
AZ
#4
What kind of MPG's do you get now?

GM TBI is just a "dumb" electronic fuel dumping carburetor and look at the size of the TBI's small 2 barrels vs. a 4 barrel carb. A GM TBI 454 is a disappointment over a 4 barrel carb. 454's eat fuel and deserve the well earned reputation for doing so. The reputation is eating the same amount of fuel loaded or not. No reason to not have power on demand (Secondaries opening up) while drinking that much fuel.

For sure aftermarket fuel injection with 4 intake holes on the throttle would be the place to start replacing a carb.
 

Tillard

New Member
Messages
17
Likes
6
Location
New Orleans, LA
Thread starter #5
What kind of MPG's do you get now?

GM TBI is just a "dumb" electronic fuel dumping carburetor and look at the size of the TBI's small 2 barrels vs. a 4 barrel carb. A GM TBI 454 is a disappointment over a 4 barrel carb. 454's eat fuel and deserve the well earned reputation for doing so. The reputation is eating the same amount of fuel loaded or not. No reason to not have power on demand (Secondaries opening up) while drinking that much fuel.

For sure aftermarket fuel injection with 4 intake holes on the throttle would be the place to start replacing a carb.
4 intakes hole fuel injection system to replace the carburetor?
 

Tillard

New Member
Messages
17
Likes
6
Location
New Orleans, LA
Thread starter #6
What kind of MPG's do you get now?

GM TBI is just a "dumb" electronic fuel dumping carburetor and look at the size of the TBI's small 2 barrels vs. a 4 barrel carb. A GM TBI 454 is a disappointment over a 4 barrel carb. 454's eat fuel and deserve the well earned reputation for doing so. The reputation is eating the same amount of fuel loaded or not. No reason to not have power on demand (Secondaries opening up) while drinking that much fuel.

For sure aftermarket fuel injection with 4 intake holes on the throttle would be the place to start replacing a carb.
TBI may not be that advance from the carburetor but their still simple to work on along with simple start up than the "choking" or "dieseling" carburetor
 
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