Author Topic: Big block with auto.  (Read 2852 times)

mrdetails

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Big block with auto.
« on: March 13, 2007, 04:17:49 PM »
Hello all: Is it true that a  big block with auto trans and power disc brakes would have had 2 brackets under the rear carb bolt? 1. Power brake pipe to hose. 2. Kick down switch bkt. If not where was the power brake pipe mounted?Did they use a different pipe?
Thks.:
Sam

JohnZ

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Re: Big block with auto.
« Reply #1 on: March 14, 2007, 03:52:14 PM »
The A.I.M. (M40, A9) shows the kickdown switch bracket on the driver's side rear carb stud on all big-blocks, and in (J50, A4) shows the power brake pipe & support bracket in the same location for all big-blocks, but there's no illustration reference in either section that shows both parts used together. Since the switch location is important and its bracket is flat, and the power brake pipe & support location isn't critical and it has a raised rib on it, logic would say the power brake pipe & support went on top of the kickdown switch bracket.

Maybe someone with a power brake big-block automatic can confirm? KurtS?
'69 Z/28
Fathom Green
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KurtS

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Re: Big block with auto.
« Reply #2 on: March 15, 2007, 08:46:18 PM »
Though my car is pretty original, that area of the car has been changed and the kickdown was missing. So no help, sorry.
Kurt S
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169INDY

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Re: Big block with auto.
« Reply #3 on: March 16, 2007, 03:55:11 AM »
The mounting bracket for the Kick down switch has a mounting Tang (outboard), that is bent down and interlocks with a hole in the base of the carb (outboard of the rear carb mounting stud hole) (Mine is a quadrajet 4MV) this tang keeps the switch and bracket from rotating and maintains the switch in-line with the actuating arm that is mounted on the throttle shaft. The kickdown switch bracket must be installed under the power brake pipe tube mounting attachment.

P.S.
The switches are servicable, by carefully peening open the Zinc case, you can access the internals and burnish or buff-bright the stationary and sliding copper contacts and relube the switch for care free operation. Make drawings or notes on assembly order and do not stress the zinc case. It can be done (I HAVE REWORKED 2 SWITCHES) and save tons on purchasing a replacment from E-PAY!

I assume a 1969 Holley equiped, 396/375-TH400 with kick down would be same, not sure if the mounting bracket is identical or not.

My source is my 1968 396/325-TH400 I have had for 24 years.

Jim
Jim
68 SS/RS L35 Th-400 LOS
69 Pace Car L48 Th-350 LOS

mrdetails

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Re: Big block with auto.
« Reply #4 on: March 16, 2007, 04:07:03 PM »
Thanks all. I'll install the kick-down switch first.
Sam

nuch_ss396

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Re: Big block with auto.
« Reply #5 on: March 16, 2007, 07:28:45 PM »
The mounting bracket for the Kick down switch has a mounting Tang (outboard), that is bent down and interlocks with a hole in the base of the carb (outboard of the rear carb mounting stud hole) (Mine is a quadrajet 4MV) this tang keeps the switch and bracket from rotating and maintains the switch in-line with the actuating arm that is mounted on the throttle shaft. The kickdown switch bracket must be installed under the power brake pipe tube mounting attachment.

P.S.
The switches are servicable, by carefully peening open the Zinc case, you can access the internals and burnish or buff-bright the stationary and sliding copper contacts and relube the switch for care free operation. Make drawings or notes on assembly order and do not stress the zinc case. It can be done (I HAVE REWORKED 2 SWITCHES) and save tons on purchasing a replacment from E-PAY!

I assume a 1969 Holley equiped, 396/375-TH400 with kick down would be same, not sure if the mounting bracket is identical or not.

My source is my 1968 396/325-TH400 I have had for 24 years.

Jim

The L/78 ( Holley ) bracket for the kick-down switch is different.
69 SS 396, Hugger Orange, D/80, D/90
Chambered Exhaust, N/66, THM400, 3:73 posi

Steve A.
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