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1994 Silverado 5.7 Question

Join Date: Jun 2008
Posts: 1

June 29th, 2008, 8:45 PM   #1  
1994 Silverado 5.7 Question

I Just bought this 94 silverado extended cab 5.7 truck and it just doesnt seem to have much power it only has 102k on it and has been very well taken care of. But I used to have a 1998 Silverado Z71 with the 5.7 Vortec in it and that truck had a ton of power and was an animal this 94 seems to lack the power that i used to have. I know the 94 is a throttle body and those suck but is it really that much of a difference???? If anyone knows please let me know I just am curious if there is something wrong with the truck. Like i said the power isnt bad but its nothing compared to the z71 i had. Also if i bought a vortec 5.7 would i be able to just drop it right in and no problems or is this going to be a serious project??? Thanks let me know if anyone has an idea about any of this.

Join Date: Jun 2008
Posts: 75

June 30th, 2008, 9:16 AM   #2  
RE: 1994 Silverado 5.7 Question

try to run some cleaners through the system and see if that helps any. Also, check the engine itself to see if anything is loose damaged etc. You never know what might be the problem if there is any. There is not THAT much of a difference in the two. I have a 92 350 throttle body that can hold it's own with my 95 Z71

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June 30th, 2008, 1:04 PM   #3  
RE: 1994 Silverado 5.7 Question

well the tbi 350's were around 220 hp and the vortec 350's were around 250-255hp. so a 30-35hp jump is anoticable difference. the tbi truly will feel less powerful. but they were good for their day.

you might look into what gearing you have. if the 98 had 3.73's and the 94 has 3.42's it will make a difference also.

i know my dad's 03 with 3.73 gears feels a little more responseive off the line and towing than my 06 with 3.42's. although i have 295hp vs his 285.

Join Date: Feb 2008
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July 1st, 2008, 6:19 AM   #4  
RE: 1994 Silverado 5.7 Question

The non-Vortec TBI 350's (pre 1996) were rated at 200 hp (310 ft-lbs torque). Theadditional 50 hp from the Vortecs makes a huge difference in performance. And, like bad2006z71 stated, differences in gearing may add to your performance woes.

Don't beat-upthe throttle body system to much unless you've spent a lot of time with carburetors. The response from a (stock) throttle body compared toa (stock) carburetorsetupwas night and day, in its day...

At 102,000 miles, a good tune-up (if not already done) would certainly be in order.

Join Date: Oct 2007
Posts: 3

July 1st, 2008, 8:15 AM   #5  
RE: 1994 Silverado 5.7 Question

I can say that gears, intake, headers, and maintenanced tuneups are what give the 89-1996 C/K more power. That vortec is a strong motor and yeah a swap should be easy, but the other vehicles in that time rangeare better at pulling. Speed wise and power wise you have to do those upgrades

Troublesome94k1500's Avatar
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Join Date: Jan 2014
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January 25th, 2014, 12:06 AM   #6  
Need advice please!

I just purchased a 94 k1500 with a 350tbi and 700r4 trans from a friend. The issue is that it when I start it the engine runs very low rpm.. close to 250rpm and after 5-10 seconds the check engine light comes on and it revs to about 1000rpm. It does burn some oil but its got 238k on it. I put new oil, plugs, and air filter on in the last week and nothing changed. Also it stalls sometimes when going down hill? Any ideas?

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February 22nd, 2014, 3:09 PM   #7  
i also have the same problem as you, trouble. I've come to the conclusion that it has something to do with your knock sensor telling you that you have a misfire. pull the coil, plugs, wires, distributor, cap and rotor apart and clean all that corrosion off with a file if need be. check for corrosion where the distributor mounts as well. don't be afraid to move your ground to the next header bolt after you clean it completely. don't forget about the firewall and trans ground on the same side in the back.
your positive battery cables to your starter and such can also rot and cause the whole vehicle to stop working when it shorts on something.
good luck, brotha. you will notice it shifting better after you do all of this.
let me know if you got further than i did though

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