5.7 vortec more info please (1 Viewer)

[88chevota]

Ok So I have a 91 5.7 TBI in my cruiser. my sister has a 1999 suburban. The engine was rebuilt. 30K on the clock. was bored out a little. Just got in an accident. The insurance totaled it. I am getting the whole burb for $1300 from their insurance. Tranny has 98K on it.

The short of it is should I sell the vortec engine and buy something to go with my TBI set up, or just swap in the vortec? I have over 200k on my 5.7TBI... still runs great.

What would be the benefit of the vortec over the TBI setup and vice versa?

suggestions would be great.

I will be parting out the burb for whoever wants full power leather seats and such

 

[Elbert]

I would run the TBI until you have issues. The advanatage to the vortec is a good bit more power, but also more complexitity and cost. Far more complicated to work on, you'll need a new wiring harnes and PCM (you can rob that off teh donor to some degree), you'll need the PCM programmed. I would just ride with the TBI for now.

You might consider robbing the vortec heads and using the GM special intake manifold on your TBI...

 

[Kurtis]

It might be cheaper and fairly easy to just get a special tbi intake for the vortec motor in the suburban and put your tbi setup on the new motor. You get more power lower miles and don't have to mess with the wiring or buying a new fuel pump. You can get a new chip for around 200$ custom programmed. tbichips.com has a lot of good information on it. Theres only a couple of other small mods to make the tbi keep up with the higher flowing heads. Pretty much boring out the throttle body a little and cranking up the fuel pressure. With that combo and a new cam you could have 300-350 hp and 400lbs of tq with your tbi.

 

[Medusa]

Swap in the Vortec and forget about it. You don't need a new harness or PCM. Passlock will need to be disabled in the PCM and the OEM harness can easily be modified. If you keep the tranny from the Burb, you wold have to make only a few minor changes. It really is not that difficult.

 

[88chevota]

Swap in the Vortec and forget about it. You don't need a new harness or PCM. Passlock will need to be disabled in the PCM and the OEM harness can easily be modified. If you keep the tranny from the Burb, you wold have to make only a few minor changes. It really is not that difficult.

I like your simplicity. I think the same way. so how do I disable the passlock? I am keeping my th350 tans since I have the 203/205 combo behind it.


Sorry guys your other ideas sound cool but that means spending more $$$. I want to do this for little to no extra cost. If I just leave both alone I can sell one and regain some $$$.

I don't want to be taking parts from one and put them on the other.

My main questions here are:
Just swap in the 99 vortec or sell it and buy a built long block for my TBI set up?
Can I get enough $$$ from the 99 vortec to buy something worthwhile for my TBI?
Keep in mind the 99 vortec has been bored out and only has 30K on it. My motor has 200K+

 

[Medusa]

Passlock is disabled by reprogramming the PCM.

 

[88chevota]

Passlock is disabled by reprogramming the PCM.

can I reprogram it or reset it with any OBDII scanner? or do I need to get a new chip burned? Or do I need to bring it to a specialty place and have them reprogram it?

 

[Elbert]

In my note above I did not intend to infer you need a new wiring harness...but you certainly will need the one from your donor and woll most lilkely need to modify it to make it work, or you will need to buy one from the various vendors who make them. IF you are not a wiring pro or understand all the sensors, and emissions crap its likely you would be better off having someone mod your donor harness or buy one outright.

I don't think swapping over to a Vortec can be down for small $$.

The PCM's on the vortec have to be programmed...they don't use PROM chips like the older ECMs did (TBI).

TO have the PCM programmed you need to understand what sensors you plan to use, what transmission you are going to use and if you plan to scrap any of hte emissions stuff.

I would download the manaul from the painless web site that talks about their harness (free download) last time I looked...it will give you some ides of the sensors invovled with the vortec. (get the one that deals with the 5.7 vortec).

If you want something simple I would stay with the TBI. I htink you would be well served to better understand the vortec swap before jumping off into that...and what emissions rules may come into play. Vortec uses 4 O2 snesors, cat converters, a couple of dedicated emissions related sensors, fuel tank pressure sensor, and the varous other ones that drive the fuel injection. Is is true that some of the sensors can be deleted through the PCM programming but that all depends on what you plan to do, and what your emissions rules require.

The TBI can run all day without issue with a fully modified exhaust and as I recall it has one 02 sensor and just a handful of other sesnors...very dependable..but not a powerhouse. You'll save yourself some money by staying with what you have.

 

[hankinid]

You'll also want to consider replacing the intake manifold gaskets on the Vortec if they haven't been done in maybe the last 30 to 50K. Check the snap-in heater connector on the forward passenger side of the manifold...they rot, a stainless fitting fixes the issue.

If you use the '99 tranny, have it gone through before installation...4L60E's sometimes have issues around 100K.

You can swap in a gm high output alternator with a slightly longer serpentine belt.

Steve