86 Factory TBI?? Keith?

[Tony_SS]

How is it that I have an 86 and its a TBI? It appears to be a factory setup although the engine has been replaced with a GM crate. I can post pics... any idea's on how mines the only 86 TBI that I've heard of? Maybe this is a question for Keith.

[tvblazer78]

Originally Posted by Tony_SS

How is it that I have an 86 and its a TBI? It appears to be a factory setup although the engine has been replaced with a GM crate. I can post pics... any idea's on how mines the only 86 TBI that I've heard of? Maybe this is a question for Keith.

How long have you had the truck? And it not hard to change it over, post some pics..

[LiveAnimals]

What is the build date?

http://www.lmctruck.com/icatalog/cc/full.aspx?Page=11
http://www.lmctruck.com/icatalog/cc/full.aspx?Page=12

This is the best I can do, as far as I know it was only an option in 87

[JohnC]

Sounds to me that someone has changed it over. Like TV said it wouldn't take much.

[f.monroe]

Member Bigarmzz had a late build 86 4x4 that was a factory built TBI truck . I think I remember that right .I am under the assumption that some of the very last built 86's were TBI since the new 87's were about to come out . They must have started the changeover on the assembly line already . I would say that if your truck has a July 86 build date it is probably factory .
Frank

[Keith Seymore]

Originally Posted by f.monroe

Member Bigarmzz had a late build 86 4x4 that was a factory built TBI truck . I think I remember that right .I am under the assumption that some of the very last built 86's were TBI since the new 87's were about to come out . They must have started the changeover on the assembly line already . I would say that if your truck has a July 86 build date it is probably factory .
Frank

No - we did not do that ( build a few TBI trucks in late '86).

TBI came out in '87 in preparation for the '88 GMT400 trucks. Said differently, we didn't want to have an all new truck and an all new powertrain in the same year, so we brought the TBI out a year "early" in 87 to get field exposure.

I remember thinking "...ugh - I will be SO GLAD when this model year is over!". It was such a big deal, being "hi tech" and all...

K

[Keith Seymore]

Originally Posted by Tony_SS

How is it that I have an 86 and its a TBI? It appears to be a factory setup although the engine has been replaced with a GM crate. I can post pics... any idea's on how mines the only 86 TBI that I've heard of? Maybe this is a question for Keith.

Sounds to me like somebody replaced it and just did a really nice job.

K

[Keith Seymore]

Originally Posted by Keith Seymore

No - we did not do that ( build a few TBI trucks in late '86).

TBI came out in '87 in preparation for the '88 GMT400 trucks. Said differently, we didn't want to have an all new truck and an all new powertrain in the same year, so we brought the TBI out a year "early" in 87 to get field exposure.

I remember thinking "...ugh - I will be SO GLAD when this model year is over!". It was such a big deal, being "hi tech" and all...

K

Caution! Off topic story to follow:

Incidently, the day I moved from the assembly plant into Truck Engineering was the day they announced the split into two organizations: the old "R/V" truck (obviously the carryover C/K version) and the new GMT400 group. There was a lot of whispering and speculation among the rank and file as the players on the two teams were divided up.

I had no idea of the significance at the time and didn't understand all the political "ins and outs". My only thought was "...PLEASE don't send me back to the assembly plant!".

I stayed with the R/V truck, btw -

K

[f.monroe]

Originally Posted by Tony_SS

How is it that I have an 86 and its a TBI? It appears to be a factory setup although the engine has been replaced with a GM crate. I can post pics... any idea's on how mines the only 86 TBI that I've heard of? Maybe this is a question for Keith.

What is the vin number of the truck . If it decodes as a 5.0L then it may be a factory carb engine . If it decodes as a 350 I would think it is a factory install .
Frank

[Tony_SS]

The vin is: 1GCDC14H8GS122750

Build date is 10/85 and I looked on the glove comp and it lists a 305, 3 spd tranny. It has a 350 700R-4.. with on OD gear selector even! I think someone did a really nice factory job when they put the drivetrain in.

[f.monroe]

Originally Posted by Tony_SS

The vin is: 1GCDC14H8GS122750

Build date is 10/85 and I looked on the glove comp and it lists a 305, 3 spd tranny. It has a 350 700R-4.. with on OD gear selector even! I think someone did a really nice factory job when they put the drivetrain in.

Sounds like a nice install . Enjoy the TBI .
Frank

[Tony_SS]

Honestly, its hard to tell the difference btw it and a carb IMO. I do know that the right tank hesitates bad, and when I try to switch tanks its slow to switch over and gets hung up. Hopefully that's not too big of deal to fix.

[bigarmzz]

my 86 4x4 was 100% stock truck...i bought it from the original owner, and it was def tbi 350...it had a date of something like 9/86 if i remember right

....it only had around 75k miles on it and was mint mint

i just lifted it a little and put on 35" tires

[Damien]

[QUOTE=bigarmzz;3397446]my 86 4x4 was 100% stock truck...i bought it from the original owner, and it was def tbi 350...it had a date of something like 9/86 if i remember right

....it only had around 75k miles on it and was mint mint

I'm think a 9-86 build date would make it a 1987 model year. The new models come out in August.

[suicide 63]

Just a thought ,could of been a vin swap.Check the frame vin if you find time If your curious.

[Captkaos]

The late 86 models had TBI on them like Bigarmzz. I have seen and heard of several like this. They typically have been 1987 VIN titled as 1986 on most.

[Keith Seymore]

Originally Posted by Captkaos

The late 86 models had TBI on them like Bigarmzz. I have seen and heard of several like this. They typically have been 1987 VIN titled as 1986 on most.

Wow. I sure don't remember that.

I checked around here a little to see if anybody else that worked on the program is still around. Most of the guys I thought of have retired, some recently.

If I can find someone to ask about this I will let you all know.

K

[Keith Seymore]

I did send some emails out and got some very good replies back. I will post them here (with minimal editorial commentary) for your evaluation and opinions:

Kevin Snider - VIN release engineer (Kevin took over for the VIN expert I was trying to reach. The VIN engineer establishes the VIN breakdown and coding that you are familiar with and makes sure the VIN is in compliance with any legal or regulatory requirements):

[Quote]Keith,

There have been times when options or parts were released for a particular model year and then a decision was made to move that option or part ahead to the current model year using a TWO/supplement WO. So, what might seem as a 1986 vehicle built as a 1987, could be the option pulled ahead on a 1986 vehicle.

I do not think it is legal to sell a 1986 vehicle as a 1987. There are VIN laws and Emission laws that will not allow more than one January 1st in a model year build cycle.

Just some thoughts,

Kevin [end quote]

Keith's Note: While I agree with the VIN laws and Emission laws comment I do not think the January 1st rule would be an issue here (because of the short build timeframe). We have done this in the past and did take that into consideration when releasing the 2002 GMT820C (Cadillac Escalade), which started production January 2nd of calendar year 2001 as a (extended) 2002 model.

Craig Mantey (Calibration Engineer):

[Quote]Hello Keith,
> I may be able to help you as I was the calibration/development
> engineer doing the production cal for the 1987 L19 (7.4L big block
> with TBI). It has been awhile, and I don't recall exact dates, but I
> can tell you we certified the TBI package for a 1987 release (1987 SOP
> was probably in the July-September 1986 timeframe). Although this was
> in calendar year 1986, it would have been for the 1987 model year. I
> don't recall any "late 86 models VIN'd as 1987's, thus I would agree
> with you - but that was 23 years ago and I often question my memory !
> ! ! I won't say it's impossible, but that's my recollection. I'll
> forward this to Mr. Dennis Heeger (now retired) who was the program
> lead at that time to see if he can weigh in as well (Hi Denny).
>
> Hope this helps
> Creig[quote]

Denny Heeger (Program Lead for the TBI application):

[Quote]My memory is probably in a flux, but as most find when they get older
the old things some what lurk in the back ground. Only records will show
what happened back then. There were no early releases on the Big Block
by me. There was in fact a delay with the introduction of these vehicles
because EPA did not have the facilities to test them, as is normally the
case. Lou Faix was the lead 1/2 staff Engineer coordinating the
approval with EPA. Lou was the GM rep to the Automotive Group which
dealt with EPA.

Dennis Heeger[end quote]

Keith comment: I should point out that these answers were specific to the Big Block program, by the guys that worked on those engines. Timing for the small blocks could have been (and often was) different.

Additionally, it should probably go without saying, but I trust we all recognize that the calendar year and the model year are different. As mentioned earlier, the model year normally starts in the August/September timeframe. But also, as I mentioned, we can really start the model year whenever we want as long as we stay within any legal or regulatory guidelines.

HTH -

K

[Greenlee]

I graduated high school in 87' and I have a memory of a kid I went to school with who got a brand new 86' model Silverado that was TBI. He got it for graduation and my memory is that it was an 86' model. I have mentioned this to friends of mine who are also 73-87 chevy truck fans and no one believes that it was an 86' model. All these years I have thought that there were a few late model 86' models that were fuel injected.