Anyone running that Holley 670cfm TBI throttle body? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

redz 1970 K5 · 10-19-2006, 10:56 PM

My truck has been idling rough, and the fuel injectors are actually starting to get noisy. I just recently replaced the original fuel filter after about what, 20 years? I could barely blow through it.

Anyways, the fuel injectors are about $120/ea for a decent OEM equivalant, so I did a search on ebay, and low and behold a new Holley TB for my truck for $199 buy it now + $20 shipping. This same TB is $420+ from Summit Racing.

It is a direct bolt on for my truck with new injectors included and I think the throttle body even has an adjustable fuel pressure regulator. They claim 25% HP and torque, but as far as I am concerned as long as I don't lose anything, I will be very happy.

C&C Chevy · 10-20-2006, 11:44 PM

Can you self tune? Heard they will cause a rich condition that requires some tuning ability. I'm interested if anyone has first hand experience as well.

btw, I saw those TBI's on ebay earlier to and it appears to be a great deal. I about pulled the trigger and got one, but I ran across this and am reconsidering.

http://www.fullsizechevy.com/forums/...d.php?t=217904

Farmer Mike · 10-21-2006, 01:05 AM

Even though Holley says that it's a direct replacement, it's too damn big for a 350! I did have mine on my truck for a couple of years before I tuned it. It blew black smoke while warming up and while it ran OK afterwards, the gas mileage was fairly low.

Now I can get 20+ MPG on the highway! I used to have a crazy timing curve programmed that made it run great, but the mileage went WAY down. I'll play with it again after I get a higher stall torque converter.

My honest suggestion would be to rebuild your stock TBI and use it until you're serious about more HP. Then the Holley would be a good choice.

** Redz, Here's a suggestion. Take a look at the spray pattern of your injectors. If you have leaks (dripping along with the spray), thats probably due to bad o-rings. If the spray pattern is an inverted cone, it's working fine. Get a rebuild kit and spend a few hours cleaning it up. From what I've experienced, it's good to change your fuel filter once a year. Maybe sooner if you like to run your fuel level lower than 1/4 full. Nice rebuilt injectors on Ebay for $124 if you REALLY think they're bad.

Mike

bigarmzz · 10-21-2006, 09:42 PM

i've heard the same thing..they run rich, and your economy go's "ka-put"

it'd probably work well with a custom burned chip

10-19-2006, 10:56 PM	#1
redz 1970 K5 OBS guy Join Date: Jun 2004 Location: SoCal Posts: 1,060	Anyone running that Holley 670cfm TBI throttle body? My truck has been idling rough, and the fuel injectors are actually starting to get noisy. I just recently replaced the original fuel filter after about what, 20 years? I could barely blow through it. Anyways, the fuel injectors are about $120/ea for a decent OEM equivalant, so I did a search on ebay, and low and behold a new Holley TB for my truck for $199 buy it now + $20 shipping. This same TB is $420+ from Summit Racing. It is a direct bolt on for my truck with new injectors included and I think the throttle body even has an adjustable fuel pressure regulator. They claim 25% HP and torque, but as far as I am concerned as long as I don't lose anything, I will be very happy. __________________ 88 Suburban Goodies- Alpine, Auto Meter, BDS, Bilstein, B&M, BFG, Borgeson, Bushwhacker, Cowl hood, Flowmaster, Genuine Gear, Holley, Infinity, JVC, K&N, MB Wheels, MSD, Pioneer, Skyjacker, Sony, Thorley, Walker + more

10-20-2006, 11:44 PM	#2
C&C Chevy Registered User Join Date: Feb 2003 Location: Midwest City, OK Posts: 1,001	Re: Anyone running that Holley 670cfm TBI throttle body? Can you self tune? Heard they will cause a rich condition that requires some tuning ability. I'm interested if anyone has first hand experience as well. btw, I saw those TBI's on ebay earlier to and it appears to be a great deal. I about pulled the trigger and got one, but I ran across this and am reconsidering. http://www.fullsizechevy.com/forums/...d.php?t=217904 __________________ Robert Current: 1986 SWB Silverado 4.3 / TH400 Past: 1985 SWB Silverado 305 / TH350 - sold 1995 1987 1/2 ton Silverado - FI 350 / 700R4 sold 2007

10-21-2006, 01:05 AM	#3
Farmer Mike Registered User Join Date: Aug 2003 Location: Colorado Springs, Co Posts: 20	Re: Anyone running that Holley 670cfm TBI throttle body? Even though Holley says that it's a direct replacement, it's too damn big for a 350! I did have mine on my truck for a couple of years before I tuned it. It blew black smoke while warming up and while it ran OK afterwards, the gas mileage was fairly low. Now I can get 20+ MPG on the highway! I used to have a crazy timing curve programmed that made it run great, but the mileage went WAY down. I'll play with it again after I get a higher stall torque converter. My honest suggestion would be to rebuild your stock TBI and use it until you're serious about more HP. Then the Holley would be a good choice. ** Redz, Here's a suggestion. Take a look at the spray pattern of your injectors. If you have leaks (dripping along with the spray), thats probably due to bad o-rings. If the spray pattern is an inverted cone, it's working fine. Get a rebuild kit and spend a few hours cleaning it up. From what I've experienced, it's good to change your fuel filter once a year. Maybe sooner if you like to run your fuel level lower than 1/4 full. Nice rebuilt injectors on Ebay for $124 if you REALLY think they're bad. Mike __________________ 1987 Chevy 4X4 350 TBI with TPI heads, Crane Powermax 2030 Cam, Edelbrock 3704 Intake with 2" bores, Holley 502-6 TBI, Hedman hedders, and DIY custom chip (Hopeless .BIN addict). Last edited by Farmer Mike; 10-21-2006 at 01:24 AM.

10-21-2006, 09:42 PM	#4
bigarmzz Registered User Join Date: Sep 2004 Location: Elkins, West Virginia Posts: 2,542	Re: Anyone running that Holley 670cfm TBI throttle body? i've heard the same thing..they run rich, and your economy go's "ka-put" it'd probably work well with a custom burned chip __________________ 1987 350 TBI lowered 5/7



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