[Gmecm] Chevy 350 Carburated to TBI / TPI?

Tue Jan 9 01:30:38 UTC 2007

It shows the
"HOLLY MANIFOLD BOLT PATTERN ONLY
Q-JET MANIFOLD HOLES ARE NARROWER"

Is there a schematic for that or what is the "narrower", and which holes?
I do believe the Chevy does in fact have a QuadraJet...

Jay Vessels wrote:
> Hi there!
>
> Here is the adapter on the FTP site:
>
> ftp://ftp.diy-efi.org/uploads/tbiadapter.jpg
>
> Or, if you can handle the file as a drawing:
>
> ftp://ftp.diy-efi.org/uploads/tbiadapter.dwg
>
> Jay Vessels
> 1982 Chevrolet S-10 Sport, 2.8V6 TBI
> 1984 Chevrolet S-10 Blazer Sport, 2.8V6 (TBI pending)
>
> Aphelion79 wrote:
>> Ok, well I guess it is best to look at adapters then, I'll check the 
>> website and see if I can find that schematic you spoke of earlier 
>> guys....
>>
>> Chris Reynolds wrote:
>>> TBI was not introduced until 1987 on Fullsize trucks with V8s.  That 
>>> means that all of them had the later style "High Swirl" heads on 
>>> them.       You can however often find the 454 TBI adapter used on 
>>> the early 454s for a song.
>>>
>>> Aphelion79 <aphelion79 at cox.net> wrote:
>>>   Whoops, to finish that... so at the Junkyard look for a TBI'ed 
>>> truck, latest model being a '86, for the whole setup... anyone have 
>>> pictures of the differences or is there some big obvious thing I 
>>> could notice?
>>>
>>> Aphelion79 wrote:
>>>  
>>>> Yeah, depending on prices of the adapters (compared to prices, if I 
>>>> can find any, of some junkyard intakes for the correct years) I'll 
>>>> probably go that route... The engine is brand new with less than 
>>>> 300 miles on it... so everything about it is currently in near 
>>>> pristine condition last time I checked...
>>>> Jay Vessels wrote:
>>>>   
>>>>> Hi there!
>>>>>
>>>>> No need to swap heads. There are several options for the 
>>>>> TBI-specific intake:
>>>>>
>>>>> 1) Grab an adapter to bolt the TBI to an existing 4bbl. intake. 
>>>>> Holley, etc. make them, or make your own -- there is a drawing on 
>>>>> the GMECM website's incoming directory somewhere.
>>>>>
>>>>> 2) Grab a stock TBI intake from a mid-80s fullsize truck. These 
>>>>> are likely to be hard to find, since by '87 GM went to centerbolt 
>>>>> valve cover heads which have a different angle on the four center 
>>>>> intake bolts.
>>>>>
>>>>> 3) Grab an intake from a newer ('87-, but not Vortec) car/truck 
>>>>> (i.e. F or B body, or fullsize truck) and redrill the center 
>>>>> boltholes. I've done this but do not like it at all. Getting the 
>>>>> bolts drilled right isn't fun, and I made special washers to sit 
>>>>> under the bolt heads to make sure there was enough surface for 
>>>>> clamping. Personally, I would not do this again.
>>>>>
>>>>> 4) Buy an aftermarket intake for a TBI and older heads. Holley 
>>>>> 300-49 is a choice.
>>>>>
>>>>> If I was on a tight budget or if I had a really nice intake, I'd 
>>>>> do #1. I might do #2 if I got really lucky in the salvage yards. 
>>>>> Otherwise, I'd do #4.
>>>>>
>>>>> For TPI, it's a similar issue. 1985-1986 baseplates will bolt to 
>>>>> the heads you have, but after that they're designed for centerbolt 
>>>>> heads. These may be easier to modify, or mix-and-match 
>>>>> runners/plenum/baseplates based on what you dig up.
>>>>>
>>>>> Jay Vessels
>>>>> 1982 Chevrolet S-10 Sport, 2.8V6 TBI
>>>>> 1984 Chevrolet S-10 Blazer Sport, 2.8V6 (TBI pending)
>>>>>
>>>>> Aphelion79 wrote:
>>>>>     
>>>>>> Is this possible? I have a 79' Chevy C20 sitting in my back yard 
>>>>>> with a carburetor that sucks. About 300 bucks for a new one... so 
>>>>>> I was wondering can I take the head off of a newer model truck 
>>>>>> with a 350 and TBI (or off a car with TPI) from the Junkyard and 
>>>>>> if it will bolt on directly without any problems?
>>>>>>
>>>>>>
>>>>>> *I realize I also need the wiring harness and computer (I've done 
>>>>>> a few FI swaps on vehicles already, but this one seems to be the 
>>>>>> easiest looking like everything will bolt right on...)
>>>>>>         
>>>>> _______________________________________________
>>>>> Gmecm mailing list
>>>>> Gmecm at diy-efi.org
>>>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>>>
>>>>>       
>>>> _______________________________________________
>>>> Gmecm mailing list
>>>> Gmecm at diy-efi.org
>>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>>
>>>>     
>>> _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>>
>>>  __________________________________________________
>>> Do You Yahoo!?
>>> Tired of spam?  Yahoo! Mail has the best spam protection around 
>>> http://mail.yahoo.com _______________________________________________
>>> Gmecm mailing list
>>> Gmecm at diy-efi.org
>>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>>> Main WWW page: http://www.diy-efi.org/gmecm
>>>
>>>   
>> _______________________________________________
>> Gmecm mailing list
>> Gmecm at diy-efi.org
>> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
>> Main WWW page: http://www.diy-efi.org/gmecm
>>
>>
>>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>