Demon 750 on a 12 sec 360 jet size?

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A360

Benton
Joined
May 31, 2006
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Location
Perth, Western Australia
G/Day fellas

Just had a 2nd hand Demon 750 given to me to replace my 830 too big annular holley on my 360.
It is on and running fine but seems to be much too rich ,so I was going down in jet sizes then I had a thought to ask you fellas ,someone would have been there and done that with a similar combo such as I have.I did bollow a holley 750 DP with 80's all round which ran a 12.7@109 at the track but have heard the Demons are not the same hence the question.

Question is what jet size or range for the following

750 Might Demon on a
360
10.5 CR
Torker 2 intake
extractors into 2.5 twin
727 3000stall
3.9 gears in a 9''

1970 Valiant Hardtop (Dodge Dart)
Have run 12.7 @ 109 with 1.9 60'
with holley 750DP 80 size jets

Thanks guys in advance

Benton

Copy of normal_20070217_IMG_0113.jpeg
 
The 750 Demon is likely going to be too big too. The Demon carbs are wet flow rated and the 750 you have is more like an 800 Holley.

I tried a 725 Demon on my 360 and could never get it sorted out to run right below 2000 rpm.
 
my friend runs that holley 830 on her 360 and runs 11.50's with 12:1 compression. the holley 750 sounds better. i agree with dave, forget the demon.
 
Dont have much choice due to $$$$$ issue I have the demon but what I have found out so far that I have jet a few sizes below that a holley of the similar size.

Thanks for the feedback so far

Benton
 
my 750 mighty demon came with 76 83 jets.
i have a wide band air fuel meter and those jets were to rich at WOT, since found 72 79 works for me in the southwest.

360 .30 over stock build
low compression
mild cam 480 480
eddy heads
high rise
tti's 3in x pipes
4.11 3800 stall
daily driver

no 1/4 times
 
my 750 mighty demon came with 76 83 jets.
i have a wide band air fuel meter and those jets were to rich at WOT, since found 72 79 works for me in the southwest.

360 .30 over stock build
low compression
mild cam 480 480
eddy heads
high rise
tti's 3in x pipes
4.11 3800 stall
daily driver

no 1/4 times
love that car! :)
 
Finally checked the jet sizes yesterday.
77 front 89 rear

Dont know what this was running on before but certainly does not suit my application.

Trying 73 front then using the 77's for the rear as a base to work from.

Then tune up or down.

Benton
 
Finally checked the jet sizes yesterday.
77 front 89 rear

Dont know what this was running on before but certainly does not suit my application.

Trying 73 front then using the 77's for the rear as a base to work from.

Then tune up or down.

Benton

You are on the right track now - maybe 72/80s - it is a 750dp Speed demon?
maybe try #35 squirters too. make sure fuel is level in the centre of the windows.
 
G/Day Fellas

just an update on the 750 demon and the tuning of it to suit my 360.

After trying a variety of jet sizes I have ended up with the fllowing;

Front jets 80
Rear jets 81

the thing is flying now and puling right through to redline in each gear except top (keep running out of road)

So it only took me a few months ,admittedly on and off to get to this point.

But it is running hard now

Nostalgia Drags 2007 015.jpg
 
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