What is the difference between 1996 and 1997 Vortec?

[Back N Black]

While researching my 96 2 door a while back, I learned that ofcourse 96 was the first year of the Vortec. Cool. After further research, I see a 5 HP difference between 96 and 97+. Now, from what I've read, the "sawteeth" casting on the end of the heads is a sure sign of Vortec heads. Yeah, mind don't have these. Casting numbers come back as Vortec though. Did they revise the head design between 96 and 97? Is that what accounts for the 5 HP bump? Or was it something else, like a different cam? I can't seem to find a good breakdown of all the engine specs/parts.

To further complicate things, I just did a search to show the 5 HP difference I am talking about. According to Wikipedia, the Vortec was first used in 95! Ok, so was it a mid-year change? Secondly, it shows the HP to be 255 HP from 95-99.

Now, MotorTrend confirms the 5 HP difference between 1996 and 1997. I'd really like some more info on this!

 

[Kenny D]

What year did they go from TBI to the spider injectors?

 

[95escahoe]

What year did they go from TBI to the spider injectors?

95 was the last year for the TBI 96+ was the Vortec with the spider injectors


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[Back N Black]

95 escahoe, your reply to Kenny reinforces everything I have known about the switch from TBI to Vortec. That Wikipedia link I posted though, shows differently. Ofcourse anyone with an account on their site can edit it, and put incorrect information on it.

 

[east302]

Here is GM's literature for 1996, shows the 350 at 255-hp, so I'd think the Motor Trend article was just based on the wrong info.

https://www.gmheritagecenter.com/do...its/Chevrolet-Trucks/1996-Chevrolet-Truck.pdf




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[ScottyBoy]

The info about the Vortec engine dating back to 95 might be referring to Vortec engines in general, not just the V8. I know that the V6 Vortec started in 95, so that's possibly where they get the 95 info from.

 

[Back N Black]

Could be. Like I said, anyone can modify the entries on Wiki, so someone may have used some bad information. The Vortec V6 goes back to atleast 94 though. My Sonoma was a 94, built in the summer of 93, and it had the Vortec 4.3L V6.

 

[ScottyBoy]

Could be. Like I said, anyone can modify the entries on Wiki, so someone may have used some bad information. The Vortec V6 goes back to atleast 94 though. My Sonoma was a 94, built in the summer of 93, and it had the Vortec 4.3L V6.

I didn't know they actually started in 94. My mom had a 95 Astro and it had the Vortec V6 in it. But the 94's still had the TBI 4.3 V6 in them.

 

[Back N Black]

Yep, they did build the Vortec V6 in 94, if not earlier. My truck would have been the TBI. At that same time, there was also the "Enhanced 4.3L," I believe it had 10-15 more horsepower. Visually, the air intake was different. The one I had, had the traditional air cleaner. The Enhanced 4.3 had an air box, with a tube connecting the piece on top of the TB. The Enhanced version may have had the spider injection. This could have been used as a way of testing out that style of fuel injection, before incorporating it into the V8.

Coincidentally, there is quite a fandom for those Astros. There are plenty of owners who collect and build them, and they do quite a bit of work to the engines.

 

[ScottyBoy]

Coincidentally, there is quite a fandom for those Astros. There are plenty of owners who collect and build them, and they do quite a bit of work to the engines.

Yeah I know that there is a big fan base for the Astro and Safari vans. I used to be on a Astro and Safari vans forum and there were several guys who even stabbed LS V8 engines in their Astro van.
But I was on there because I was constantly repairing that van for her. She bought the van in 99 with a blown engine for $800, spent about $2500 on the new engine and essentially had a 5 year old van with a new engine for just over $3k. But then other shit started breaking and then I truly realized that the previous owner beat the shit outta that thing which explains why he blew up the engine at less than 75k miles.