DeTomaso Mailing List: July 99, Message #1101

Steve, 

Here's some of the Motorcraft carb info from the page I'm working on.  It
appears you should have
a squarebore carb and intake as shown in the chart below.  I have a
squarebore intake in perfect
shape (cleaned and repainted) if you're interested.  It's either date coded
for '70 or '71, I'll have to 
check.  

Dan Jones
  
Motorcraft 4300 and 4300D

Ford replaced the Autolite 4100 with the Motorcraft 4300 and a spreadbore
version, the 4300D.  Most 4V 
Clevelands were fitted with one of the Motorcraft units.  Both the 4300 and
4300D use air valve secondaries 
with fixed jets and power valve enrichment.  The 4300D has the standard
Holley/Autolite bolt pattern which 
is unusual for a spreadbore and means they will not directly mount up to
most spreadbore manifolds, other 
than factory Ford intakes.  The only aftermarket intake manifolds that I'm
aware of that will directly mount a 
spreadbore 4300D are the Holley Street Dominators and Strip Dominators.
They have a trapezoidal plenum 
opening that will clear the large secondary butterflies.  However, other
intakes can be made to work using 
an adapter spacer.

Model	CFM	Venturi Diameter	Bore Diameter
	primary	secondary	primary	secondary

4300	441	1	??	1 7/16	1 9/16	67-68 302 J-Code
4300	470	1	??	1 7/16	1 9/16	69 351W
4300	595	1 1/4	??	1 9/16	1 11/16	69 390 S-Code
4300	600	1 1/4	??	1 9/16	1 11/16	70 351W, 351C
4300	605	1 1/4	??	1 9/16	1 11/16	71 351C
4300D	715	1 1/4	??	1 9/16	2	71 Boss 351C, 
	72-74 351C

4300's have a reputation of developing leaks at the front of the carburetor
between the lid or air horn, and 
the main body. If you plan on modifying your engine, remember the selection
of power valves is very 
limited so it will be difficult to tune properly.  Also, there are no books
on the market for modifying or 
performance tuning the Motorcraft carbs.  Your best source of information is
a Ford factory repair manual.  
Jack DeRyke thinks they are an instrument of the Devil :-)

Only the early model 4300's have adjustable secondary air valve.  The
adjustment procedure is:

1. Loosen clamp screw and let housing rotate to no load position.
2. Hold air valve in closed position.
3. Scribe reference mark.  
4. Rotate nylon spring housing counter-clockwise the proper number of knobs
and then tighten screw.
5. For 1967-1968 applications the proper number of knobs are:

	289 manual 5 knobs
	289 auto 4 knobs
	390 7 knobs
	410-428 8 knobs 


> So can anyone definitively tell me
> 1) what is the correct manifold for my car (square or spread)?
> 2) what would the casting codes be (D1ZE, DOAE, etc)?
> 3) what is the correct carb for this, and also what
> would it's tag marking be ??
> 4) finally, where can I get correct date coded parts
> to put my car back to stock?
>