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Vortec Heads


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#1 crue98

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Posted 09 September 2004 - 09:48 AM

I was wondering if any of you have put Vortec heads on a 5.7 TBI engine. I have been looking around to put a little more horsepower into the stock engine. Let me know if any of you have done this and what the results were. Also any other mods to your TBI that makes a difference in performance. Interested in finding out some info


Thanks
98 LTZ 3.8

#2 maroonsilverado

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Posted 09 September 2004 - 10:44 AM

i have a friend that put the vortech heads on his 93, but he changed the intake at the same time. so im not sure if the vortech heads will work with the TBI intake. for what you're going to spend on some vortech heads you could probably get your current heads ported/polished/shaved, get about the same outcome, and still have a little money in your pocket.

this same friend also put a big cam in the engine. it didn't run right at first, but he replaced the MAP with a new design that tricks the computer into thinking there's enough vacuum and it runs great now. at first he just unplugged the MAP and it ran fine.

pullies, exhaust, headers, chip, cold air intake, ignition upgrades (wont give you power but will help feel what ya got). and if you got the money you could always scrap the TBI and buy you a multi-point. edelbrock makes one and it's only like $2500 :thumbs:

#3 crue98

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Posted 09 September 2004 - 11:15 AM

you do have to change the intake if you swap for the vortec heads. i don't think the factory intake that comes on the truck match up the the vortec heads. i have been searching different things to get some more performance of of my truck- 94 Z71 5.7- and can't really decide what would be the the right mod for it without empting my savings. The Edelbrock MPI is way out of my price range.
98 LTZ 3.8

#4 BOFH-Z71

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Posted 09 September 2004 - 02:22 PM

you do have to change the intake if you swap for the vortec heads.  i don't think the factory intake that comes on the truck match up the the vortec heads.  i have been searching different things to get some more performance of of my truck- 94 Z71 5.7- and can't really decide what would be the the right mod for it without empting my savings.  The Edelbrock MPI is way out of my price range.

<{POST_SNAPBACK}>



He's correct...Factory intake does not match up.

I had a 90 w/ 5.7 TBI that I was going to put the Edel MPI on it, but decided to rip out the computer and put a 4Bbl Carb on it w/ Performer RPM heads and a new roller cam. Was cheaper than buying the heads plus new intake/inj system.

Edited by BOFH-Z71, 09 September 2004 - 02:23 PM.


#5 crue98

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Posted 09 September 2004 - 02:47 PM

He's correct...Factory intake does not match up.

I had a 90 w/ 5.7 TBI that I was going to put the Edel MPI on it, but decided to rip out the computer and put a 4Bbl Carb on it w/ Performer RPM heads and a new roller cam. Was cheaper than buying the heads plus new intake/inj system.

<{POST_SNAPBACK}>

[/quote]


What was the difference in performance after doing this mod? Was there more horses and did the MPG go down after the switch?
98 LTZ 3.8

#6 BOFH-Z71

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Posted 09 September 2004 - 06:57 PM

What was the difference in performance after doing this mod?  Was there more horses and did the MPG go down after the switch?


Well considering I went from a ~400CFM 2Bbl TB to a 650 4Bbl Carb w/Mech Secondaries, there was a hugh drop in MPG. I got about 9MPG in town, and about 12-14MPH highway. Performance was awesome though... was killing fox body stangs all the way up to 70MPH or so.. I don't have any good 1/4 mi times cause I couldn't keep the 700R4 in the truck, and I didn't have enough stall for the engine

This is what I had on the truck back when I had it in 99-00

Engine

350 2Bolt-Main
282/288 .510/.520 Cam
Roller Lifters
Roller 1.5 Rockers
Performer RPM Alum Heads
2.02/1.60 Valves
Performer RPM Manifold
Holley 650 4bbl Carb
MSD HEI Ignition
MSD 9mm Wires
4 Core Radiator
Hi-Flow Water Pump
Braided Hoses
16V - 270A Alternator

Driveline:

T-700 with:
Corvette Servo
Upgraded Piston
High Strength Bands
High Strength Clutches
Improved Front Pump
Street/Strip Shift Kit
3.73 Gear Set
Auburn Posi-Trac
Anti-Sway Bar
Drop Springs

Exhaust:

Afterburner Headers
Header Wrap
Hooker Mufflers
Full 3in Pipes
Hi-Flo Cat

Edited by BOFH-Z71, 09 September 2004 - 07:00 PM.


#7 rascalsweet

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Posted 09 September 2004 - 08:30 PM

they made a eldebrock intake that bolted up to the vortec heads that was for a carb. was supposed to be a cheap upgrade for the upgrade vs. price. that was for pre-vortec engines of course.

#8 BOFH-Z71

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Posted 09 September 2004 - 08:48 PM

they made a eldebrock intake that bolted up to the vortec heads that was for a carb. was supposed to be a cheap upgrade for the upgrade vs. price. that was for pre-vortec engines of course.

<{POST_SNAPBACK}>



They make one for the LS1s too. It will adapt a Carb to the 5.7 LS1 blocks for use in older muscle cars.

Edited by BOFH-Z71, 09 September 2004 - 08:48 PM.


#9 crue98

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Posted 10 September 2004 - 07:50 AM

There is a place advertised on E-bay that they bore out the TB and bore out the intake. When they bore the TB it goes from 420CFM to 850CFM. Then they bore the intake intlets so that the TBI and the intake inlets match up. They said with the TB bore that there is 15-20hp gain from it.

Here are the sites for each

http://cgi.ebay.com/...7919642857&rd=1





http://cgi.ebay.com/...7919645101&rd=1
98 LTZ 3.8

#10 1992z71

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Posted 29 September 2004 - 03:37 PM

i am in the process of adding vortecs to my 92. I have added a 670 holley throttle body. Made a big difference. I also added the 300 horse 327 cam and it really woke it up. When you change the cam around you have to play with the computer chip. http://www.cfm-tech.com/catalog/ check out this site it will help you a lot. They can help you with the performance up grades you are looking into.

#11 St_Anger

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Posted 03 October 2004 - 08:47 PM

I think you guys are looking for this.

Posted Image

More info!! :cool:
1992 Rustang LX...Gone soon hope to forget... *cough junk cough*
1989 Black&Tan S15 Jimmy 4x4... Gone and really want back!!

#12 americanmuscleman

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Posted 17 October 2004 - 08:13 PM

I tried a whole slew of parts on my 95' TBI 350.

At first I added a dual flowmaster exhaust, Stage II Fastchips chip (Ed Wright), K&N and intake tube, and a 180 thermostat. I made the truck pull a little better on the top end, but you have to run 91+ octane or it pings when under load.

After that I decided to get more serious. I added TrickFlow aluminum heads (2.02in/1.60ex), a custom Erson roller cam and roller lifters, JBA shorty headers, Catco high flow Y-pipe and cat, Edelbrock Performer TBI intake, custom chip from a guy in Cali that is no longer in business, and a bunch of small stuff like an adjustable fuel pressure regulator, injector and throttle body spacers, etc...

The truck had considerably more power, but was still not as fast as a Vortec 350 (I could never figure out why?). It had a load of torque though. The midrange torque was awesome (2100rpm to 3000rpm or so). It pulled my 5000lb boat so much easier.

The downside to the upgrades I made is that my gas mileage was never good. I got about 12 to 13mpg on the highway normally and about 11 in the city. The upside to it was everyone always asked me, "is that thing cammed?"

To be honest, trying to get good power out of a TBI 350 is hard. You'll wind up throwing a lot of cash at a TBI 350 and it will never make the power a Vortec will if you keep the throttle body injection... but thats just my 2 cents.
Steve
2004 GMC 2500HD SLT, CC, SB, 4x4, LLY D/A, Carbon Metallic ext. / Dk Pewter int.