New K3500 - Need More Oomph - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1972RedNeck · 05-28-2017, 08:26 PM

Just got a smoking deal on a '98 crew cab K3500 with the L29 7.4 Vortec. It has 260K miles but it is CLEAN. Supposedly the transmission was bad - turns out the drain plug fell out of the Borg Warner t-case. $300 junkyard t-case and it runs and drives great.

Been driving it around a bit to see if I am going to flip it or keep it. I'm thinking this one needs to stay and one of my Fords will have to leave

.

But as with any vehicle that gets added to my fleet, it needs to have a bit more power than stock. From what I have read, a tune is definitely worthwhile (gets rid of torque management in OD as well, correct?).

What about headers though? I'm not interested in long tubes, but shorties would be an option. I have read conflicting views on shorties, some saying they are a big gain and others saying either go long tubes or nothing.

Thoughts?

As for the tuning, who can get me the best tune for a stock L29? Sending off the computer is no problem if need be.

**special-K** · 05-29-2017, 07:43 AM

Get all the air in you can for starters. I'm sure you knew that.

RatPwrd72 · 06-01-2017, 04:58 PM

I used BlackBear Performance to do the tune on my '96. I had the TM removed as well as the rear cats and EGR. It felt snappier and didn't downshift as much towing my enclosed trailer around. I still had the stock exhaust system on there, so I switched to a Magnaflow muffler and removed both cats. This for sure helped it breath.

Mine is a 2wd, 4L80E, 4.10 gears. Running the stock tire size it got 10 mpg empty and jumped up to almost 13 after the tune, exhaust and a new AC-Delco air filter (it had a K&N that was filthy when I bought it).

IMO, the price of the tune is well worth it.

Headers should be another increase in power and MPG, but I haven't really thought about it. Especially after pricing a name brand long tube for this truck .

hotrodron · 06-04-2017, 08:56 PM

That sounds good i need to do the same on my truck have you ad trouble with the injectors or water leaks on intake manifold

RatPwrd72 · 06-06-2017, 10:48 AM

Quote:

Originally Posted by hotrodron

That sounds good i need to do the same on my truck have you ad trouble with the injectors or water leaks on intake manifold

I haven't. Mine has a GM crate that was put in just before I bought it last year. Pretty sure they didn't do anything with the injectors, just stuck them on the new motor.

Tom · 06-10-2017, 02:42 PM

Quote:

Originally Posted by RatPwrd72

Mine is a 2wd, 4L80E, 4.10 gears. Running the stock tire size it got 10 mpg empty and jumped up to almost 13

Annnnnnd I'm never getting a big block haha. That's just terrible.

05-29-2017, 07:43 AM	#2
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,859	Re: New K3500 - Need More Oomph Get all the air in you can for starters. I'm sure you knew that. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

06-01-2017, 04:58 PM	#3
RatPwrd72 Registered User Join Date: Jan 2005 Location: Maysville, OK Posts: 227	Re: New K3500 - Need More Oomph I used BlackBear Performance to do the tune on my '96. I had the TM removed as well as the rear cats and EGR. It felt snappier and didn't downshift as much towing my enclosed trailer around. I still had the stock exhaust system on there, so I switched to a Magnaflow muffler and removed both cats. This for sure helped it breath. Mine is a 2wd, 4L80E, 4.10 gears. Running the stock tire size it got 10 mpg empty and jumped up to almost 13 after the tune, exhaust and a new AC-Delco air filter (it had a K&N that was filthy when I bought it). IMO, the price of the tune is well worth it. Headers should be another increase in power and MPG, but I haven't really thought about it. Especially after pricing a name brand long tube for this truck . __________________ 1972 Chevy Cheyenne Super- Pump gas 496,TH-400, TCI Stall, 3.73's,Ochre & White two-tone w/Olive Interior 1967 Chevy Short Step Drag Truck-Iron Headed 468 Making Memories My momma took me off the bottle years ago.....

06-04-2017, 08:56 PM	#4
hotrodron Registered User Join Date: Oct 2015 Location: BAKERSFIELD Posts: 36	Re: New K3500 - Need More Oomph That sounds good i need to do the same on my truck have you ad trouble with the injectors or water leaks on intake manifold



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