99' Tahoe 5.7 Vortec power upgrades

[99Yuk]

When was the new design introduced? Where is it available to purchase now, GM or the aftermarket?

Not sure when it was introduced, but it's available in California under warranty still even today. We talked about where to buy it a few months ago HERE. I found it at amazon for the guys here. It was the cheapest place to buy in the US. It's made by Delphi which makes other GM OEM parts.

It's a good upgrade to do when/if your intake is apart.

 

[SunlitComet]

release in about 2002-2003

 

[wcole35]

That is exactly what i was looking for! Thanks Everyone. I am getting anxious about this now. Also i am now looking into which headers to buy. Any suggestions. I live in Washington and have to renew my tags every year.

 

[97yukon]

i am installing a lt4 hot cam with my stock heads very soon. i hear the heads on the l31 flow great but the intake sucks. so ill upgrade the intake when i can come across some more greenbacks. as far as cold air intake goes i have always felt like it is a waste of money to but a 300 dollar intake to gain 3 more hps compared to a ebay creation lol. buy the cheapy. your not going to see any crazy gains from and air intake...the most you will see is a louder exhaust tone and some air sucking when you hit the gas lol.

 

[Blind]

don't bother with shorty headers, longtubes with a nice x-pipe crossover with magnaflo cats into a borla/dynomax/magnaflo muffler is the way to go for exhaust.

I replaced the top end of my tahoe w/ the 5.7L vortec recently because of a cracked head and was looking into cheap mods to do at the same time, and ended up doing none of them.

the lt4 cam requires machine work to the valve seats to fit higher rated springs, the stock heads can't easily swap valve springs. Higher ratio rockers can't be swapped on either, even 1.6's are too much for the stock valve springs.

The only intake "upgrade" compatible with the stock computer is the marine vortec intake which is damn near impossible to find. 2 of the injector tubes on the stock spider of my truck were totally clogged, so I did the MPFI upgrade.


IMO, $3500 should be enough to get a motor out of a 99+ truck and swap it in, a nice 6.0L and 4l80e would be a much better way to spend your money, and they are much easier to mod later on.

 

[atis]

I will disagree with you on the shorties...yes, compared to long tubes they suck...compared to the stock restrictive headers they are a huge plus. I cant leagally run long tubes and pass the visual inspection so I went with shorties. I love them. Better throttle response, smoother idle, and better sound. Now did I gain HP or TQ? Maybe a couple but a couple is better then nothing. Plus they look waaaay better then the crappy stock headers.

 

[wcole35]

I am actually going with the E-Tec 170 heads. I am having my cam worked so no need to buy a new one. I also must use the shorties do to inspections every year. I am looking at a x-over and mag cats and muffler. getting custom exhaust do to knowing a guy and the motor is going to be bored out to 3" exhaust so i kinda gotta.

 

[TigerEyz3]

Though they cost more than shorties (and many long tubes), I've been very happy with the Thorley Tri-Ys (mid-length headers). I spent extra and got the ceramic coated variety. They replace everything from the manifold to the converters. Had 'em for ~7yrs and they still look the same as the day I installed them (and we use salt in the winters, not for the snow, but the ice). ;-)