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  1. #1

    Default My first 1998 Chevy 6.5 turbo dully

    Well in new to this side of the forums. Iím looking at purchasing a 19984 door Chevy 3500 dully super clean truck. My intent is to use the truck to pull a trailer withmy mud truck or one of my race cars on it. I have been looking for bolt onparts but have hade no luck. What all is out there injectors pumps is there abolt on exhaust and can I intercool the turbo and get some more power?
    2000 Ls s10 V8 extended cab drag truck
    1999 s10 Ls Droped 2.2L
    1998 s10 blazer red stock

    1985 s10 blazer 5 speed v8
    1982 4X4 355ci 450hp k1500 trail truck
    1978 4x4 short bed F150 460ci 540hp mud truck on 38.5 super swampers boggers

  2. #2


    There are a few things you can do with a 6.5L but you will not find plug-in programmers, nor should you expect huge power gains like you can with a Duramax. Reprogramming the PCM will provide the best gains. There are no alternate inj. pumps for these, just the Standadyne 5521 electronic pump. This pump also has a limited output and usually limits the amount of HP you can gain since it can be maxed out pretty easily with programming. Keep in mind, ALL fuel to the injectors is metered by the PCM so any so-called "high output" injectors will yield little or nothing without reprogramming the PCM.

    First thing to upgrade on a 6.5L is the exhaust. Especially turbo back! The downpipe on this engine looks like GM pulled it from the scrap bin and threw it on the truck. This is a must if you look to have any other mods like installing an upgraded ECM which increases boost and fueling. Check out the 4" system from ssdieselsupply; it's a good fitting system and sounds good too.
    IMO an intercooler on a 6.5L under most normal conditions isn't worth the money it will cost, nor will it likely provide the benefit you'd expect -- it also will take up a lot of the little space you have in the engine compartment. Most kits made for the 6.5L mount the cooler below the bumper where it's likely to get damaged anyway. The only people I have seen really benefit from one consistently tow heavy and live in the southern states where they're regularly operating in high humidity and temps to begin with. For the cost, a water/meth system could probably work just as well, and do so at a fraction of the cost without taking up so much work space under the hood.

    I would be sure to first check and see what maintenance has been done on this truck. GM recommended replacing injectors and harmonic balancers every 100K. If either of these went bad you could experience severe engine damage.
    Try and see if this truck had regular maintenance to the cooling system. 6.5L are fairly well known for overheating (especially early years until '97 when they started upgrading the system), and if you tend to use this for towing make sure the cooling system has been taken care of. Ideally you want to keep these below 210F, and anything which restricts airflow through the rad. or if it had the earlier low volume water pump installed on it at any time, will compromise cooling.
    Have You Smoked A Hemi Lately? Why, Yes I Have!
    2008 Sierra RC/SB, Iron Block 5.3L(LMG)
    , 3.42, Locking Diff, HD Cooling, HD Suspension, Towing Package.
    Raptor Stainless Steel Step Bars, Folding Tonneau Cover, DiabloSport Predator

  3. #3


    I was lookind into the crossover pipe down pipe and a Silverline Universal 4in Stack kit from Diamond Eye and a cold air intake kit? If i can do the intercooler do u think this will help bring the egt temp down? Thanks for your input

  4. #4


    A larger downpipe should definitely bring down EGT's. The original one GM put on these trucks is the worst -- "what were they thinking" part.

    You can intercool it, but for the money there's probably far cheaper alternatives that will work just fine. Also, unless you're running higher boost/fuel and are working it hard in higher temps & humidity, an intercooler may not really be that much of a benefit -- again, especially for the money.
    Most I/C kits take up alot of space and mount down low where they're exposed to rocks and stuff. Concentrate on getting the exhaust gases out faster and allowing it to breath better.

  5. #5


    If you have any questions about the 6.5 see if you can find the guy DAREDEVIL on this forum. He will tell you anything you could want.They do custom built 6.5's and they do a lot of conversions so I would see if you can find him and see what he can tell you.I' about to do a 6.5 conversion and he answered all my questions.
    2000 Chevy Silverado 4WD Classic
    2'' lift Torsion Keys and air shocks
    33/12.50 Hankook Dynapro M/T
    3 1/2'' down pipe back 6" Tip
    Dodge Towing Mirrors
    Smoked Tails, Cab Lights, and Side Marker Lights
    1% Rear and Side Window, 20% Front Tint
    American Racing Wheels/ With a custom black paint
    Cold Air Intake
    Edge Performance Chip
    Custom Audio System
    LED Tails
    Black background headlights and parking lights

  6. #6


    Thanks MTM i have talked to DAREDEVIL. I do need to take to him more on this.

  7. #7


    I've been messaging him a lot so i can get going on my conversion and hes helped answer everything.

  8. #8


    If the PMD hasnt been relocated out of the engine bay that should be the first mod. Heath Diesel has the nicest PMD relocation kit and a warranty. The next mod should be a turbo back exhaust such as a Diamond Eye. After that a FeedTheBeast kit from WalkingJDesigns.

  9. #9


    Thanks SuperSport01 i was going to do the intake and exaust first.

  10. #10


    No problem I have had a 6.5td truck for several years now and have learned what works.

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