LT1 and a T56 in a 55 Chevy


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Could you add a T or Y connection that you blend outside air into the air stream before it reaches the
vents? Are you wanting the outside air to pass thru the evaporator? Guess you would also need some
kind of valve to control the amount of outside air.



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Yes I'm thinking about how to do that, but decided for now to just go ahead with the "standard" install....

I can only hope I won't mess up this install, or if I do it won't be too serious a problem, am learning a lot, over 60 pages of instructions, it's taking awhile for me to absorb all of it, and the install of the evaporator under the dash has not been easy !!!

Had to trial fit the evap unit several times without the hard lines installed, so I could locate the mounting holes in the firewall and drill them. I had previously reworked the firewall, so "unnecessary" holes got welded up!! What fun!!

These brackets look kinda flimsy to me, but it's what they came with....


This side bolts to the bottom lip of the dash....


I needed to bolt in place the two defrost ducts that came with the unit....


Of course the holes provided did not match up, so drilled some new holes....
No problem....


Putting the hard lines on the evap unit was a bit of a horror show....


These will never match that firewall cover plate


Hmmm, can't seem to get them to look like this drawing....


After lots of messing around with them this is the best I could get...


But the unit would not go in under the dash
with these hard lines installed until I cut
the firewall access hole bigger, as you can
see above, extending the hole further down,
it was the only way I could get the unit
to go in under the dash with the hard lines

It still took some wrestling around under the dash
to get it to sort of line up in the original firewall hole....


Not the best fit, but I think I can make it work....

And I had to fab a cover plate for that larger
firewall opening I had to cut....


I think I can make this work ok,
still have a long ways to go this this though....


solid fixture here in the forum
Snorkel pipe on one side from front of car under the hood and through the firewall and attach to one side of the fan housing and you can have fresh air .


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I won't....
But that's a ways away, have a lot to do before I address that fresh air issue...

New vents and cables came today....


The old stuff was pretty rusted up,
so I wanted new stuff....

The screws holding the old parts in are something
from way back, clutch head screws, they need
a special screwdriver, I dug around in my Dad's old
toolbox and found a screwdriver that would fit....
I got lucky....




Checking out the new vent cables and they are a bit too long,
for how I want to fit them in there....
so I'm going to shorten them to fit the way I want....



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I guess there is not anything you won't modify, in fact I think you purposely reject things so
you can make them better !!!

Always a pleasure to see your detailed work !


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The original cables for the vents were routed up under the dash and looped down to the vent doors, with the new Vintage Air setup there's no room for that on the passenger side, so it needs to go more direct like the pix tried to show, which will work better if I take about 4 to 6 inches out of the cable. I think the drivers side is ok as is, but haven't checked it out yet...
But yes, you're probably right on, I just love to try changing things....
When the "aftermarket" hyd. clutch master cylinder I bought hit my headers, ok, I gotta do something different, so went the that firewall mounted setup instead, which of course lead to the conflict with the RainGear wiper motor setup, they were pretty easy to modify to fit though...
This AC system, it's a trip !!


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Using a new '55 Chevy Pickup dash control, it's a bit different
than the sedan control, but I think I can modify it to make it work OK !


It comes apart pretty easily,
All the old cable connections are being replaced with
electrical sliders....


The label window for the sedan version needed to be trimmed
a bit to fit into the truck control panel...


Looks good to me....


These two levers for the temp control needed to be bolted together...


This blower speed control replacement lever for the sedan version needs
to be shortened to fit this control unit from a Chevy Truck....


No problem at the knob end...


Looks good to go....


These electrical signal devices need 2" of travel and produce
a zero to five ohm signal, I think this will work just fine....



More later....

(More pix HERE if you're interested....)


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Then the "mode control" lever (air flow to dash, defrost, floor)
just below the fan speed control needed to be lengthened....


And the second resistance slider (0 - 5 ohms) mounted....




Now I need to figure out how to mount the temperature control unit...


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Got the ac to heat temp control sliders hooked up, it looks ok....


More pix here if you want....

Sorry I didn't post more, it's been a long day and I'm tired....
-2Loose Willy


The Grumpy Grease Monkey mechanical engineer.
Staff member
the pictures and info is VERY MUCH APPRECIATED!


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When I tried to fit the face plate for the controls in the dash opening,
the opening was just a hair too narrow, so much for the claim that
the '55 Chevy pickup unit will fit in the sedan!!!

The edges of the opening are rolled in, so with a body hammer,
I carefully "rolled" the left side edge until the face plate fit....


I got a good fit, now I find that the face plate for the truck is shorter
than the sedan, so there's an opening at the bottom....


Made an adapter plate to bolt the bottom of the face plate
into position in the dash, keeping the top located as
high up in the opening as I can....


Cut a piece of 1/4" aluminum plate, drilled it and tapped it to match
the two holes in the face plate and the two holes at the
bottom of the dash opening....


Had a box of various length of #12-24 screws, so used those....


It bolted right up and is nice and solid....


While I had the unit partially apart, painted everything that I could,
and reassembled it after everything was dry....


Everything is looking good, full function and movement on all controls....


Heat/cold controls (vertical sliders) all the way up at full cold


Now all the way down for full heat....


The upper controls, the fan is off, the air flow is at the dash....


Air flow (lower lever) at the dash outlets...


Fan (upper lever) at max....


How am I going to get this into the dash opening ???


It took removal of a couple of parts, some jiggling around, but I got it in....


Plugged in the control harness to the three slider units,
The controls still move nicely without hitting anything,
and the unit is mounted nice and solid....

I still have quite a bit of wiring to do before
I can put power to this unit and test it out...
Soon though....


solid fixture here in the forum
Hello 2Loose... I was gone for awhile so it took me some time to catch up on your thread. You have been busy I see!!! Keep up the GREAT work!
I like the fabbed up cover plate you made for the pipes coming thru the firewall. Nice and clean.


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Thanks man,
It's a labor of love, it's project #27 for my lifetime, gotta milk it for all it's worth, mentally....


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Back to the wiring project in general....
Looking at the fuel pump....
It came with a diagram,
a relay, and a breaker switch...


OK, here's a good question, which side of that circuit breaker
do you connect the battery side to, the bronze colored one,
or the silver colored one ??

Since the battery is in the trunk, near the fuel pump in the fuel tank,
I'm putting the relay and circuit breaker back here.
Ran a blue wire back from the dash, and will put
a toggle switch under the dash for emergency shutoff of the fuel pump !


Am thinking of just mounting both the circuit breaker
and the relay just above the battery...


There are side terminals on this battery,
I could do this hookup off of those,
but the main cables have an auxillary connector,
and I think I will just use those...


I'm looking for a nice looking box I can mount
those parts in, maybe even one that
has a logo like "condom dispenser"
or some such idiocy....

Move Later...


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The new "roll over protection" switch for the fuel pump arrived,
cut a piece of aluminum plate to hold the circuit breaker,
the relay, and the roll over switch....


Some drilling and tapping for 10-24 screws...


Bolted it in place with some wing nuts...


Now to wire it up....


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Got it wired up, wire from the dash back to the roll over protection
on the right, then to the relay in the middle.....
Then the battery connection to the breaker on the left, then over
to the relay, finally through the floor in the corner behind the battery .
inside a rubber hose, over to the fuel tank and fuel pump....


Connected a ground to the fuel pump....


All hooked up and ready to go....