408 6 pack carb jetting

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70 DDDart

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Langley, BC, Canada sometimes Ca USA
Just got my new 408 stroker assembled and I am going to run the LA six pack set up so was wondering if anyone out there has a carb tune for this setup? Specifically,What jet size for ctre carb and what vacuum spring color for the out boards?
The stroker has MP flat tappet 508 lift cam, about 9.5/1 CR, MP electronic dist and orange box. Car has 4 speed with 391 gear.
Would like to get this close initially so I can break in the motor. Once that is done I can fiddel with carbs ! I have an AEM wide band set up and put bungs in my exhaust so that will help later with tuning.
 
I would start with the small yellow spring in the outboard vacuum advance pods...
 
Id start with stock netting in the center carb, get all 6 bbl.’s to idle the engine correctly, tune the primary first, secondary second, springs last starting with the OE springs.

If spring changes cause confusion and fits, try drilling out the air bleed passage and install Holley air bleed screws to Taylor the timing and rate over the springs.

Check this out; TUNING A SIX PACK
 
Just got my new 408 stroker assembled and I am going to run the LA six pack set up so was wondering if anyone out there has a carb tune for this setup? Specifically,What jet size for ctre carb and what vacuum spring color for the out boards?
The stroker has MP flat tappet 508 lift cam, about 9.5/1 CR, MP electronic dist and orange box. Car has 4 speed with 391 gear.
Would like to get this close initially so I can break in the motor. Once that is done I can fiddel with carbs ! I have an AEM wide band set up and put bungs in my exhaust so that will help later with tuning.

The wideband will be key to getting dialed in. It is an absolutely invaluable too. Getting your float levels right is critical too. Your break in will be on the center carb anyway, so bumping the stock jet size up a few sizes may get you up and running without worrying about running too lean for the first 20 minutes.

Make sure you optimize your initial, mechanical and vacuum advance to what the motor wants once you get the flat tappet broken in and before you start messing with fine tuning the carbs.
 
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