Is there any truth to the story that some of these 95 tbi vans slipped through with vortec heads? It seems a bit far fetched to me considering that they would change tooling for possibly a couple thousand or so custom tbi to vortec intakes? Or change tooling to drill and tap a few sets of heads out of thousands and thousands of the same casting. Any thoughts on this are welcome, if it is true I'd like to see proof though, not s rebuilt engine someone put vortec heads on but a real deal from the factory 1995 tbi with vortec heads.
98 Dodge shorty hitop mark iv 95 Chevy van 20 regency hitop conversion van
Never saw a '95 Vortec 5.7. Would be nice if they did since we own a late production '95 G20 conversion. But it's not Vortec. Although some of the late '95 Chevy/GMC vans were sold as '96s. They were almost always G20/G30's and mostly aftermarket conversions and/or utility vehicles such as ambulances. It was not too uncommon to see a G30 extended being sold as a '96 because that's what the paperwork labeled it. Most of those were beat to death as work vehicles.
Last edited by CatFish; February 23rd 2019 10:35 am.
It's not about GM doing extra machining to make them fit, it's about running out of old parts they no longer want to use. 95 was a transitional year like 83. Look at the born on date at the drivers door jam, was it made in 94 or late 95? There is no telling when they ran out of old engines, only they know that. If made in late 95 it may be possible. The vortec has 4 bolts a side, the earlier heads have 6. Look for the triple hump casting at the end of the heads (front- back).
While I don't "know", my gut is no, not possible from the factory.
GM Powertrain is as interested as any business in wisely using up old stock, and minimizing scrap.
But yes, intakes are different. GM did not tool up and cast TBI injection intakes to Vortec heads prior to the introduction of Vortec heads. While it would later become a popular conversion, never happened in production. Even IF they had the intakes, and they ran out of swirl port heads (why would this happen?), they would not be able to sell the combo due to lack of emissions and MPG testing. The Govt. puts the modern manufacturer through all kinds of hell to get certification of these engine combinations for emissions. Then the potential change in MPG numbers, which are CLOSELY monitored for CAFE.
If you were asking me if this could happen in 1965, I'd day yes. And we see many items from the muscle car era that were not supposed to be, but did happen. But not by the '90s.
Just took a set off my 95' G30 and they definitely are not vortec heads. I almost cant give them away. Casting # 14102193. Not very sought after it seems.
Yes, not much demand for them in the performance world. You might find someone with an old TBI engine that needs a set, but as you have found...very low demand.
No sir, 96+ = Vortec. Now, with that said, vehicle manufacturers tend to build for the model year prior to that years start, so theoretically a Sep or Oct 1995 produced head could be an actual 1996 Vortec, but they should be easy to spot. Here's a good vid on some tips.
I pulled the heads off my 1995 this winter and went with vortec style. That change and the roller cam swap was worth 40hp and 50 ftlbs of torque across the curve starting much lower than the factory curve, that is huge when you are towing. You can possibly run the combo on the stock tbi chip but it is not recommended. You can only see the gains once everything is dialed in properly. The only old body style G van to come with vortec heads is the 1996 box vans that were carry overs from the 1995 year. Not too many were done this way.
What are swirl port heads? The crate Goodwrench engine I bought said it had them. It was a350. Light truck engine I put in my 90 g20. It was for 86 _95 I think. I got it from Jeg,s.
Last edited by Lionvan; May 08th 2019 11:07 am.
[IMG]A foolish faith in authority is the worst enemy of truth. Question Authority.
What are swirl port heads? The crate Goodwrench engine I bought said it had them. It was a350. Light truck engine I put in my 90 g20. It was for 86 _95 I think. I got it from Jeg,s.
There is a lot of misinformation on the net about the swirl port heads. Some say they are for mileage and torque. I got a lot more torque out of the vortec heads and the mileage is very close to the same, maybe even a bit better. The vortec heads have the more efficient chamber too. Chamber shape does make a difference.
They are a point in time. They were a way to boost port velocity (they are basically only half the width of a conventional port by the time you reach the valve). With that velocity and swirl comes a boost in low rpm torque. But like running a marathon with your nose half plugged up, they don't breath well at higher rpm. They served a purpose...with TBI, they gave very crisp throttle response, and very good low end torque.
Time marches on, and the next generation of SBC engine uses Vortec heads, the best iron SBC head GM ever produced...they had learned a lot about head flow and chamber designs in this time. They also gain roller cams of a more aggressive profile Vs TBI, and multi-point fuel injection. So torque and power are up.
In this case, newer is better, but that doesn't mean older is garbage. It just depends on your goals.