5.7 TBI to 5.3 Vortec Swap

[twomorestrokes]

Originally Posted by Chevyman15004X4

I belive it was around 1988 cars started showing up with rail injection while trucks started and just stayed with the limited TBI systems for 7 years but I am not sure about other makes such as ford and dodge. (The only good thing I can think of for the TBI system is its easier to work on then carberators and multiport. They also are more durable electronic wise due to less components and don't flood out when during very hostil off road conditions.)

Yeah, those TBI's were just slugs, due to the manifold and restrictive cylinder head design, among other things. My truck was a '95 and while it ran great, I spent a lot of $$ on Gibson headers, exhaust sustem, air intake modifications, etc trying to get it to move. The '96 Vortech was tons better, with better flowing heads, multi-port, etc. I was just getting ready to install a set of '96 heads with a GMPP intake to accept the TBI when I gave up and got different trucks. My wife's 5.3 and my 6.0 are much more efficient and powerful than the dinasaur. I really had to have my foot into the '95 to get it to run like these do just under normal driving conditions.

[pies]

one other consideration is the exhaust system on the 95 tbi only had 1 o2 sensor and the newer engine has 4, you will need to change that also

[Chevyman15004X4]

Originally Posted by pies

one other consideration is the exhaust system on the 95 tbi only had 1 o2 sensor and the newer engine has 4, you will need to change that also

On that problem, I will just take a few nuts that the o2 sensors will screw into and weld them on the exhaust pipes after I drill a hole in them. Problem solved. (I hope.) If there is a reason this won't work, please let me know.

[who fan]

Originally Posted by BlenderWizard

Well, numbers wise, the 5.3 has the 350 beat all around if you compare the 5.3 to the last year the 350 (5.7L) was used in the trucks.

My right foot can`t read numbers lol.
It has been a while since I drove a 5.7. But I remember my old one feeling stronger than my 5.3. I just got my 01 I`ll have to warm up to it I guess. I found out a lot of things that disturb me about the 99 up Chevys. I hope my choice proves to be good. I liked the 88-98 models. My previous truck was a 93 Ford, never knew what was going to happen next to it. From what Ive read, the 97-03 Fords are very good trucks.I liked my 88 chevy better than my 93 Ford so I went back to chevy.

[Chevyman15004X4]

Well, I compared my tuck with the 350 tbi to my parents avalanch a few week ago and I noticed a big difference expecially when passing. I have never been from 50 mph to 90 mph in a truck that quick since eveything I have driven has been the 350 or 4 bangers.

Are you sure your 5.3 is working properly or your 5.7 wasn't modified because when I went back to mine after driving my parents, I went from great acceleration with 18 mpg to super slugis and 12 to 14 mpg. I wonder if the rear ends make that big of a difference.

[who fan]

Originally Posted by Chevyman15004X4

Well, I compared my tuck with the 350 tbi to my parents avalanch a few week ago and I noticed a big difference expecially when passing. I have never been from 50 mph to 90 mph in a truck that quick since eveything I have driven has been the 350 or 4 bangers.

Are you sure your 5.3 is working properly or your 5.7 wasn't modified because when I went back to mine after driving my parents, I went from great acceleration with 18 mpg to super slugis and 12 to 14 mpg. I wonder if the rear ends make that big of a difference.

My 5.3 is quick in the higher RPMs but off the line and down low I remembered my 5.7 being stronger. My 5.3 has the 3.73 rear end I dont know what my 5.7 was. The 5.3 is the extended cab the 5.7 was a regular cab so that might be the difference. My 5.3 runs smooth as silk it would be a nice engine if not for the knock at start up. That really ruins it for me.

My 350 had 188000 miles ran like a top. With the rattling the 5.3 does I`d be surprised if the longevity would be nearly as close, it has 57400 on it. I like the idea of having cast iron over aluminium for heads.

[Chevyman15004X4]

Who Fan I did notice that the 5.7 does have alot of low end torque expecially with a loaded trailer but it falls dramaticly as the rpms increase and thats where i belive that the 5.3 really has the advantage is at high rpm. And since the 350 tbi only had about 3 grand to play with redlining at 4 grand, it was very limited with most of its torque seeming to be around 2 grand and anything over 2 and expecially 3 grand was like almost complete power loss.
Also, If anyone wants to keep in touch with me, I might scrap the thought of the project and get a chevy avalanch 2500 with an 8.1 Liter engine and 4X4. If any of yall are interested, I will sell you (if I don't do the project that is) the engine, transmission and all electronics for the same price I purchased them for which is $2600 but you do your own shipping. The engine only has 1100 miles on it. It came out of a wrecked 2004 Suberban that was hit in the side with rear frame damage so it was totaled. The vin number from the vehicle is (3GNEC16Z74G104471). So if your newer chevy or GMC truck has lots of miles and is in need of new engine and or tranny, let me know on this forum and I will give you my phone number. This engine and tranny should swap stright in a newer chevy truck, (wont fit without modification into older truck that are 1998 and older) I have the receipt.

[KEVINS800]

have you done anything with the swap?

thinking about putting the new 5.3 with trany and transfer case into my 94 k1500? let me know what you've done?

you can buy the wiring harness with a new computer for 400-600!

[sak22]

In my opinion, I would stick with the 5.7 TBI... they are tried and true. With a good tune-up you can improve your fuel economy.

If it's more power your looking for, there are many aftermarket bolt-on accessories you can install.

If it's fuel economy your looking for, give it a good tune-up and switch out the intake manifold with an Edelbrock Performer TBI. These things are great for a few more MPG.

I have an 89 C1500 with 122,000 original miles and it has the 5.7 TBI 350. Currently I'm pushing about 325HP with many bolt-on accessories and a new 4L60e transmission. The one thing that has impressed me the most though is the Edelbrock Performer TBI intake manifold. My gas mileage has improved significantly, especially on the highway. Pre-manifold swap MPG was 12 HWY/9 CTY. Now I'm getting 17 HWY/13 CTY! I just completed a trip from Texas to New York and averaged 17-18 MPG on the highway at 65MPH. That's damn near as good as the brand new 2006 models! I know cause I just bought one.

Hope this helps.

[horse482]

If you want to do the swap that's your choice, I wouldn't do it. For instance, the 350 vortech is using a distrubutor and the 5.3 vortech is using coil packs. The 350 has ONE signal wire to tell the coil to fire, the 5.3 has EIGHT signal wires, and as said above the motor, and trans mount up diffrent, you will have to move the trans cross member back a couple of inches. If you have the time and the money go for it. By the time you fab up new mounts, and buy a wire harness, you will be better off buying a newer or new truck, you will have more money in the truck than it is worth. Also according to my Spec sheet the factory rated HP on the 350 for that year is 240hp. If you do the swap let us know how it go's.

[rpmchev]

I just posted a similar forum before finding this one? I am in the same position. I have some motor and tranny problems in my 95 suburban and have a new 5.3 vortec available out of an 03 suburban. Any follow up on this? Did you do it? If so.... please give some advice. thanks

[silverado122775]

Originally Posted by who fan

My 5.3 is quick in the higher RPMs but off the line and down low I remembered my 5.7 being stronger. My 5.3 has the 3.73 rear end I dont know what my 5.7 was. The 5.3 is the extended cab the 5.7 was a regular cab so that might be the difference. My 5.3 runs smooth as silk it would be a nice engine if not for the knock at start up. That really ruins it for me.

My 350 had 188000 miles ran like a top. With the rattling the 5.3 does I`d be surprised if the longevity would be nearly as close, it has 57400 on it. I like the idea of having cast iron over aluminium for heads.

The 95-99 with the 5.7 had 335 ft lbs of torque
The 99-04 with the 5.3 had 325 ft lbs of torque.

That is why the older trucks felt stronger than the news ones today.
I had a 1993 and it was very quick off the line.. not many people could beat me off the line.. but they would catch up pretty quick.

Now with the new 5.3 people are just amazed how quick these new trucks are.. Alot of people under estimate them.

[rrousou]

Well, its been a year some....how did the project turn out???

[16th hippy]

wouldn't mind knowing myself

[heavyredchevy]

Stay wth the 5.7L. The 327 is nice, but you can get more out of the 350. If i were you, id sell the 327 setup and stroke the 350 to a 383. You will never be happier I cant wait to do it myself. I have a friend that did it to his. The low end is incredable.