#21  
Old 12-11-2019, 10:13 AM
DaleW66GTO DaleW66GTO is offline
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Thanks Tom, That's a lot of information I never knew. I never meant to insinuate they made over 200 intakes as I know very little about the history of them. But I would of guessed mine was the 202 made. So I guess I accidentally was insinuating that. Thanks for explaining about the s/n's. You have a lot of knowledge about this and I appreciate you taking the time to share it with me. I will definitely do a search of BGTECH and learn more about this setup.

  #22  
Old 12-11-2019, 11:57 AM
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Originally Posted by Tom Vaught View Post
No, Mike, the engine has the PY 1st Run aluminum 1966 manifold with the custom Dashman carb adaptors, and 3 of the Holley Race 2-bbl carbs on that intake. O'Brian Truckers "Ribbed" Air Cleaners and K&N Filters.
Ribbed Air Cleaners match the Ribbed Mickey Thompson Valve Covers.

Mechanical Secondary carbs. #4782 (center) and two #4783 End carbs. I have the linkage worked out for the carbs for the BG Intake but not the fuel lines.

Tom V.

I have several sets of those #4782 and #4783 Mechanical Secondary carbs.
Some used ones that I might be willing to sell.
Tom, would love to have a set of the 4782/83 carbs but they are probably out of my budget.
I believe these are 500CFM and the secondary carbs are mechanical?
What are the differences in these and the 4412?

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  #23  
Old 12-11-2019, 04:16 PM
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Yep the #4782 and #4783 carbs would be expensive but I did modify a set of 4412 carbs for a guy and then he did not take them. Make you a deal on them.

The #4782 carb has a slightly smaller venturi vs the #4412 carb.
The #4783 carbs are not 1/3/8" venturi like a #4412 carb they are the same as the rear barrels of a #4781 carb.
Each one flows a true 425 cfm measured like a 4 bbl carb. So like having a #850 4 bbl carb and a 350 cfm carb in the center. Or as a comparison a 1150+ cfm Dominator 4 BBL carb cfm.

Tom V.

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Last edited by Tom Vaught; 12-11-2019 at 04:22 PM.
  #24  
Old 12-11-2019, 04:43 PM
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Quote:
Originally Posted by Tom Vaught View Post
Yep the #4782 and #4783 carbs would be expensive but I did modify a set of 4412 carbs for a guy and then he did not take them. Make you a deal on them.

The #4782 carb has a slightly smaller venturi vs the #4412 carb.
The #4783 carbs are not 1/3/8" venturi like a #4412 carb they are the same as the rear barrels of a #4781 carb.
Each one flows a true 425 cfm measured like a 4 bbl carb. So like having a #850 4 bbl carb and a 350 cfm carb in the center. Or as a comparison a 1150+ cfm Dominator 4 BBL carb cfm.

Tom V.
Thanks Tom,
I had a 4782 years ago that was under the seat of a farm truck I bought. Traded it for a Glock 17.

PM sent on the carbs.

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  #25  
Old 12-11-2019, 08:25 PM
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PM received, would like to get you set-up with the new 4412 carbs if that is the path you want to go down. Like I posted in the PM the Air Cleaner ring and air horns have been modded for the required clearance to fit all three on EITHER the BG Intake or on the PY 1st run aluminum intake using the dashman Holley to big Rochester adaptors.

Tom V.
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  #26  
Old 12-12-2019, 11:11 PM
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Default BG Six shooter on GA

I have one of the BG six pack set ups running on a 74 Grand Am 455. It runs well and I haven't touched it since I got the car. I didn't know these were so uncommon. I did see they were very pricey when available, I think around $3500 complete.

  #27  
Old 12-13-2019, 09:58 AM
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Quote:
Originally Posted by DaleW66GTO View Post
Thanks Tom, That's a lot of information I never knew. I never meant to insinuate they made over 200 intakes as I know very little about the history of them. But I would of guessed mine was the 202 made. So I guess I accidentally was insinuating that. Thanks for explaining about the s/n's. You have a lot of knowledge about this and I appreciate you taking the time to share it with me. I will definitely do a search of BGTECH and learn more about this setup.
It was a great idea to offer a Holley/BG carb set-up for a Pontiac but as people have posted it was expensive vs the PY intake (about $400) and using the 1966 large 2 bbl Rochester carbs that were out there.

I felt sorry for the guy who posted about his 1st run intake years ago that would not even bolt down on the Pontiac heads without machining and welding. Bolt holes in the wrong spot.

Tom V.

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  #28  
Old 12-01-2021, 10:41 AM
keith646671 keith646671 is offline
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Am actually doing a DQ setup right now for a street strip using 5499 Offy low rise and their correct adaptor kits for Holley 4365 mini q-jets rated at 450cfm ea .. expecting best case massive toe tap power but dead somewhere after 5000 rpm, actually curious where they will drop out on 444 ci with mild gears in my 71 formula.

Have been researching tripower for my 64 gto as well and was interested at making an experimental stab with a 66 factory manifold and two Rochester 2GCs on the ends and ??? in the middle. The 2 rochester I have .. one was off a very good running 455 2bbl, the other still vacuum packed rebuild duplicate still in box.

I have a mule Cutlass roundy-rounder with a 75 400 Pontiac Id like to debug both setups in and was wondering if someone could help me gather best choice parts for both and get them going. Dont have linkage for either, have correct Offy adaptors fo DQ carbs, wondering if trip carbs should/could be raised. Just ordered CD from PontiacTripower hoping to do alittle info gathering. Had seen and was considering the BG Trips setup at Butler sometime ago when carb, now there is a FI trip setup .. pretty pricey wondering if anyone here has tried .. I am scraping together both these setups on a budget thinking if I make real usable transportation out of either car I might switch to FI after carb.

  #29  
Old 12-03-2021, 04:42 PM
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I have only heard of one person who bought the EFI 'look-a-like" 6 pack carb set-up.

Not sure if it ever ran. $$$$+

MY BG / Holley set-up will go on my 64 GTO once I get the street 455 engine finished and back in the chassis with the
HO Racing headers, Nash trans, 9" rear, and stainless exhaust (VOE Tom Hand Mufflers).

Tom V.

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  #30  
Old 12-03-2021, 09:10 PM
keith646671 keith646671 is offline
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Ever see a Holley 500cfm (2300series) or fr80350 350 cfm(FR80350) Street Avenger series center and Rochester ends on a 66 factory manifold? If so is there a particular linkage/adaptor kit that makes it possible? I believe the Holley center might be easier to find parts for tho now I see the Street Avenger may flow less than a correct 2G. Possibly a velocity enhancement at low-mid RPM that would wither at higher ? In my case the Street Avenger carb at around 250$ looks promising.

Was looking at FiTech EFI setups for dual quad setup and possibly trips ... both full systems advertise 600-625 hp a range that would be a fit for reliability in a stock block. The 2000$ price-tag most likely warranted if it ends in a desirable result. The trips flows 1500cfm the dq 1700 maximum .. might possibly lose low end performance torque ?? Neither are recommended for boost. Not sure how well they bolt up to manifold.

  #31  
Old 12-05-2021, 03:25 PM
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The Holley #4412 (500 cfm) carbs (at a 2 bbl test pressure 3.0") flow about 350 cfm
each when rated like a 4 BBL carb. So about the same cfm as a 1050 dominator with the cool factor.

The #4782 is similar to the #4412 carb and the #4783 carbs have 850 cfm (#4781) type venturis and throttles and will flow more than any #4412 carb. 1-3/8" venturi for the #4412 carb and 1-11/16" (over .125" bigger venturis) on the #4783 carbs each.

I have about 10 sets of the #4783 carbs Mike. Used but in very good shape.

Tom V.

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  #32  
Old 12-08-2021, 09:47 PM
keith646671 keith646671 is offline
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Got the PontiacTripower CD and reviewed several times. I would be fine with all Rochester setup that CD covers, but am a little confused as to how to go about it most economically as Im not sure I have compatible carbs. I have 2 2gc carbs, no 2g and a 66 manifold. I see 66 linkage setups are readily available but believe they are for the exact carbs rather than a cobble together setup. Was thinking setup was 1 2g and 2 2gc before I watched CD. Appears now the factory setup is 2 2g and 1 choke stove style 2gc. for 66 manifold. Further the 2g carbs are special tri-power 2g's. No idle circuit, power circuit block off, different air horn fuel inlet?? Different cfm/bore size. Not sure how to go about finding the right carbs for my initial stab at tri-power. Would like to cannibalize the 2 2gc's I have so I only have to buy one carb. If bore size varies would like to be able to change position to get best mix since rear carb hits first. Anybody here successfully modify 3 2gc to work in tri-power setup? Is there a list of carbs that will work with tripower? possibly correct factory + known alternates that WILL work if modified? .. with attributes for identification + as needed modifications and cfm?

  #33  
Old 12-08-2021, 10:35 PM
tom s tom s is online now
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Just save your self a lot of headaches!Get the correct end carbs.The 66 can use a 350 2bbl bbl carb for the center but dont know exactly which one.On tripowers many people dont seem to find the time to do it right the first time but usually find the time to do it right the second.Mikes tripower is a good site for more info.Tom

  #34  
Old 12-08-2021, 10:38 PM
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Tom im sure will tell you tri power carbs are floes diff from 4 bbl carbs.Over the years I have found 2-4 setups are way more EZ than tripowers. BUT again you need the right carbs.Just sold my last tripower setup.Tom

  #35  
Old 12-09-2021, 12:11 AM
keith646671 keith646671 is offline
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Thanks Tom .. S .. I have heard people sometimes if not many just run on the center carb and have the ends for appearance due to cost etc. Might be a good way to get the center operating optimally. Find the right center carb, then connect/add front and rear later. Maybe I will do this now since I do have the appropriate Rochester center, I think. Might try grabbing a used 500cfm holley, rebuild it and compare the 2 on my mule roundy rounder. Just put blocking plates on front and rear. Get most performance from that setup then add booster carbs. Probably should do that even if obtain correct carbs.

It appears there is only one rod that goes from center to rear carb, then from rear carb to front. No choke or idle circuits. Or any other hookups. As long as carbs can bolt to manifold and fit fuel lines not sure it matters alot what ends are as long as linkage can open and close them.

The tripower has 6 squirts vs 2 or 4 . Squirts can be tailored with acc pump. Would consider ends mechanical secondaries(thinking 4bbl) with no air valve or vacuum break but do have squirts ... probably not too smooth once opened if not full throttle.

If I had correct carbs I would try .. but sets I have seen 1000-1500$ Almost as much as a FI setup. Less but similar dilemma to 4barrels on my DQ.

PS Not sure about NA CFM flow through tripower intake .. probably less than good 4 bbl, lower velocity larger total plenum? multiple fuel entrys less effective mixing? Have seen people say they ported and achieved gains.


Last edited by keith646671; 12-09-2021 at 12:17 AM. Reason: ps
  #36  
Old 12-09-2021, 01:08 PM
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Quote:
Originally Posted by keith646671 View Post
If bore size varies would like to be able to change position to get best mix since rear carb hits first.
Stock Pontiac Tri-Power carbs, the center carb opens a given amount and THEN
linkage opens the Rear AND FRONT CARB at the same time using a connecting linkage on the passenger side of the carbs.

Just grabbing 2 BBL carbs and trying to make something work properly is a 1 in 1000 chance of success and you would be better off with a dual quad set-up like Tom S suggests.

Tom V.

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  #37  
Old 12-09-2021, 03:32 PM
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Just save your self a lot of headaches!Get the correct end carbs.The 66 can use a 350 2bbl bbl carb for the center but dont know exactly which one.On tripowers many people dont seem to find the time to do it right the first time but usually find the time to do it right the second.Mikes tripower is a good site for more info.Tom
Time AND extra money to do it right the second (or third, or fourth, etc.) time.

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  #38  
Old 12-09-2021, 04:01 PM
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Thanks Tom V.

I was the "carb guy" in my circle of friends back in the day, loved q-jets and rebuilt several for $ at my buddy's shop in Hooksett in addition to our race crews. Mostly using Doug Roe's book. Had good results. Am curious about multi-carb setups but believe there was an industrywide change to FI for a reason. If I spent significant money on a multi I would prefer to try to modernize and use FI. I did obtain correct Offy kits to install 4360 Holley carbs on my Offy 5499 lowrise Equaflow DQ. And I have 2 2GC's in good operating condition for the 66 factory trip manifold .. I would be raising on phenolic to cure a heat evil I saw referenced in Tripower CD. CD also showed unavoidable slop in linkage causes rear to open "slightly" before front. I was figuring at speed this might be enough to change flow pattern of intake manifold.

Thought I saw you recommending 66 factory manifold and Holley center with rochester ends a few posts back vs BG setup??

My mule is a 75 400 motor so I believe I will have to grind front cover and manifold to fit 66 trip per Wallace website .. trip intake hits later front cover. Actually trip is destined for my 66 389 which supposedly trip fits on no mod per Wallace. That car a NE clambake summer cruiser 66 Star Chief probably only needs center. Got 50 feet rubber in my mule with 2bbl 71 455 2.73 welded posi. Tho not a trip manifold.

  #39  
Old 12-09-2021, 08:59 PM
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Quote:
Originally Posted by keith646671 View Post
Thanks Tom V.

Thought I saw you recommending 66 factory manifold and Holley center with rochester ends a few posts back vs BG setup??

My mule is a 75 400 motor so I believe I will have to grind front cover and manifold to fit 66 trip per Wallace website .. trip intake hits later front cover. Actually trip is destined for my 66 389 which supposedly trip fits on no mod per Wallace. That car a NE clambake summer cruiser 66 Star Chief probably only needs center. Got 50 feet rubber in my mule with 2bbl 71 455 2.73 welded posi. Tho not a trip manifold.
I recommend the Rochester 66 set-up for several reasons.

The adaptors are available to go from the 1966 Tri-power Manifold to the Holley 2-BBL carbs. The smaller Center Carb opening on the 65 and earlier intakes may position the carb in a different spot. I have never tried using a
1965 or earlier intake.

As far as the timing cover goes, the 1966 type timing cover had a relief cast in the cover so that the front mounted water gooseneck would clear the cover. You can remove the timing cover and weld a recess into the cover or you can buy a new aluminum gooseneck and grind away (mill is better) clearance in the two parts and then weld a flat piece into the modded water neck.

The Barry Grant intakes were very rare, the 1st run castings were un-useable, the 2nd run casting were un-useable, and the third run casting
were acceptable for the Pontiac application. The Chevy group of intakes may be better.

"Thought I saw you recommending 66 factory manifold and Holley center with rochester ends a few posts back vs BG setup??"

You thought wrong. I would never suggest a bastardized combination like that. All Rochester carbs or all Holley carbs is what I suggested.

Tom V.

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  #40  
Old 12-09-2021, 11:57 PM
keith646671 keith646671 is offline
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Well thanks Tom V,S. Will try to find end correct end carbs. Is there an outlet I can obtain Dashman adaptors? ... Just looked on Ebay and found Fitech adaptors to Rochester pad as well as ?? holley 2300 or 4412 to Rochester pad, pretty much same price. Will have to reread this thread several times to see if I can glean what Holley models might work best. I might change to them if I cant make what I have work. I am not afraid to try a "bastardized" mix. Applications are not my everyday transport.

Sorry I misunderstood about your 66 manifold recommendation, seeing what I wanted to see after viewing Tripower CD several times and noting rather simple connection between center and end carbs I guess. Seeing that there were slightly different cfm carbs used in various positions through the years I am not sure how critical exactly correct carb mix would be, would think if they open similarly, with similar cfm there would be similar results. Maybe this is many peoples thought process. Maybe it absolutely matters. Wish I had a list of all original carbs, their circuits if any change and cfm and how to ID them. As well as aftermarkets that have been successfully used. Going to check my 2gc as they may be marked under choke valve as to bore size(cfm).

My sister always throws a fit when we are cooking a family dinner together as we both like to try various new dishes ... she tries the original recipe first, before trying to embellish. I like to think about what might make it better and will deviate from recipe first try. This drives her crazy, which I dont really understand Her procedure is probably better, do a "control" recipe first. then embellish .. although I have had some very good and very bad results.

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