383 Vortec questions!!

[Gebo44]

I’m going to be stabbing a 383 vortec in this 99 tahoe in the next few months. I’ve watch some videos and read on it a bit but I’m wondering if there is anyone on here who has done this. I’m looking for at least 500hp eventually with the 383, EGR delete, the chip downloads and cold air intake and regearing the rearend and front diff. Who can school me some more who has actually done this. I know I’ll have to get a new ECM. I’m just used to old school 350s and old Ford motor’s. This vortec stuff just seems like there is a real limit to what can be done here. Thanks in advance for whatever info i can get.

 

[castine917]

I’m going to be stabbing a 383 vortec in this 99 tahoe in the next few months. I’ve watch some videos and read on it a bit but I’m wondering if there is anyone on here who has done this. I’m looking for at least 500hp eventually with the 383, EGR delete, the chip downloads and cold air intake and regearing the rearend and front diff. Who can school me some more who has actually done this. I know I’ll have to get a new ECM. I’m just used to old school 350s and old Ford motor’s. This vortec stuff just seems like there is a real limit to what can be done here. Thanks in advance for whatever info i can get.

Which heads and intake manifold are you using?

 

[Gebo44]

Which heads and intake manifold are you using?

I haven’t got that far. It’s no rush and it’s going to be months before I do this. Thats why I’m mentioning it now to get input. There is a video on YouTube and the guy has s 97 or 99 tahoe that did the swap to the 383. Is here to go back snd watch it but he may not have said what heads and intake. There are 383 stronker vortec motors all rest Billy on line from anywhere from about 3800 to 8000$. Heads already on.., but will need intake and all the rest of the trimmings! I’ve built 350s, 390s and 460s.., but that was a different world because of all this computer stuff and syncing on these vortecs. I would just put an old school 383 in…, but none of my gages would work and other issues. I’m just going to buy one built and install. The stock intake won’t just be used here? I thought the upgrade Power besides the displacement was in the programming on these!? Maybe you can teach me something. I’ve had three diesel trucks in the last six/seven years. The power came from the deletes and programming in the downloads. This computer stuff with these vortecs have me all thrown off here. If I get a 400-450 hp 383 vortec and hit it with the chip, EGR delete, headers, cold air intake…., followed by regearing the rear and front.., wont that give me 500+hp and the{ throw you back in the seat} feel I’m looking for? Even with the lift snd 35s!!!!?

 

[Gebo44]

Which heads and intake manifold are you using?

Sorry for that post…, I’m on my phone typing and auto-correct got me!!!!

 

[castine917]

The regearing will help with how it feels but doesn't add power.

Getting a 400-450hp 383 stroker to 500+hp may be difficult depending on what parts they used to get to their number. If they used restrictive parts than it will be easy to increase power. If they were already using good pieces than you have to use even better pieces and your improvements may still not be enough.

 

[Gebo44]

The regearing will help with how it feels but doesn't add power.

Getting a 400-450hp 383 stroker to 500+hp may be difficult depending on what parts they used to get to their number. If they used restrictive parts than it will be easy to increase power. If they were already using good pieces than you have to use even better pieces and your improvements may still not be enough.

Thanks for the response. I’ll look into what these companies are using. As far as the regearing…, it’ll help me out as far as trans.., and as far as take off Power! Pushing these bigger wheels and tires has made this motor feel like a pud!!! And it’s only got about 250hp! That’s embarrassing even saying that
My goal is 500hp and the regear. Maybe with luck ill get pretty close!!!
There is obviously alot i have to study here on this vortec upgrades and whats possible!

 

[69project]

I just installed a GM HTE383 Vortec crate motor in my '97. They advertise it as 323hp/444ft/lb torque. I have added long tube headers and used the 2002 model Vortec fuel injection system which is more reliable and supplies slightly more fuel to the engine, if I believe what I read. I still need to go get it tuned at a shop, but it runs much better than the L31 that was in there. I hope when it's all said and done, I hope to make around 350hp at the crank which suits my needs of having an older truck with some pop to it.

With that said you will need to run an aftermarket fuel injection set up/ECM or maybe go with a Procharger supercharger if you want 500hp. They advertise they still make supercharger kits for the VORTEC L31. It's around $6k but this maybe the ticket if you want that level of power without having to mess around with a custom fuel injection setup and stay with the factory setup. There is very little aftermarket support for the factory fuel injection setup. I would have dumped mine but the expensive of aftermarket fuel injection setup was not something I wanted to spend my money on.

 

[Gebo44]

I just installed a GM HTE383 Vortec crate motor in my '97. They advertise it as 323hp/444ft/lb torque. I have added long tube headers and used the 2002 model Vortec fuel injection system which is more reliable and supplies slightly more fuel to the engine, if I believe what I read. I still need to go get it tuned at a shop, but it runs much better than the L31 that was in there. I hope when it's all said and done, I hope to make around 350hp at the crank which suits my needs of having an older truck with some pop to it.

With that said you will need to run an aftermarket fuel injection set up/ECM or maybe go with a Procharger supercharger if you want 500hp. They advertise they still make supercharger kits for the VORTEC L31. It's around $6k but this maybe the ticket if you want that level of power without having to mess around with a custom fuel injection setup and stay with the factory setup. There is very little aftermarket support for the factory fuel injection setup. I would have dumped mine but the expensive of aftermarket fuel injection setup was not something I wanted to spend my money on.

 

[Gebo44]

Thank you for the response. I won’t ask what all you have invested in what you did…, but I’ve looked at it all on the net so I have an idea. I spent a few hours today looking at just getting a turnkey old school 383 with carb, a Monster or TBI 4x4 trans that will handle up to 800hp, watched videos on repositioning the trans mount, and regearing the front diff and rearend. I’ve replaced all these sensors, and keep chasing trouble coded to no end!!!! I read that with these trucks and Tahoe’s from the 90s is just Never ending! And I’ll never get the hp and feel I’m looking for. I have had two diesel pickups that I deleted, straight piped and put downloads in.., they were pushing 6-7 hundred hp and it spoiled me with that power and feel!!! I want that in this Tahoe! I think the only way is to go 383 or 454. I had NO idea before I got into this Tahoe how pussified they really were! I’ve had 80s and 70s chevy pickups back in the day that we’re bored 30 and 40 thousandths and they would burn the tires off. Hell.., I had a 63 short wide that was just Nasty with just s 40 grand bore in it, power glide and mid grade cam!!! That truck would make that heart pound when you wanted it to!!! This vortec is trash IMO!!! Yeah.., I think there will be a 383 stroker with a demon 4 barrel in the future for this Tahoe. And get rid of all these sensors on this motor/trans combo. The EPA is going to continue love me!!!!

 

[The_Family_Tahoe]

Calling @L31MaxExpress
He's had great success upgrading the GenI small block and using the existing vortec electronics.
What you want to do is possible and people have done it many times over. I would discourage you from removing the fuel injection in favor of a carburetor. Carbs have their place, but cannot compare with the driveability of a properly tuned efi. If the intended purpose of your Tahoe is daily driver, don't ditch the efi.
Lastly, just to level set your expectations, a naturally aspirated gas motor at 383 displacement will never match the torque output of a turbo diesel at 2500 rpm. It will have more usable rpm, though.
If you still want to pursue a 383, go find some of L31MaxExpess posts about his build with the search function. His rig is very similar to what you describe as your vision for the Tahoe.