Need Weber IDF Jetting Help

[Larry]

My engine has not been running up to its potential since I installed a vintage set of Weber 48 IDF's. So, I went to see an "old school" carb guy to dial-in my Webers. He said they are in need of re-jetting, but we need a good starting point...so I'm looking for advice.

My engine is a '65 289 which has been bored and stroked to 305 c.i., and in addition to the 48 IDF Webers it has aluminum heads with 1.6 roller rockers, hypereutectic pistons with 9.5 to 1 compression, hydraulic flat-tappet split duration cam, MSD ignition and the bundle of snakes exhaust. According to my engine builder, the engine should produce about 400 horsepower and similar torque.

So here is my question...what sizes should I use for the following:
choke
idle jet
emulsion tube
air correction jet
pump jet, and
main jet

I appreciate your opinions. Thanks.

 

[Dutton]

Hi Larry,

Head on over to clubcobra.com. Like you, I was searching for some guidelines as to a starting point - which is exactly what I found there.

Best of luck,

T.

 

[Neal]

Hi Larry,

I have the following setup on my 347.

38 mm chokes
65 idle
120 holder
160 air correction
145 main
55 bypass
F7 etube

I'd suggest 130 or 135 mains for your 289.

Hope this helps.