Firing up a fresh 440 + 6

[Travis Blake]

Hey gang,

I have professionally built  68 440 - 60 over bore 9:7 compression with  an out of the box 6 pack manifold and carburetors and  can't get it to run for more than 45 sec..  I have a problem with backfiring so I kept setting the timing backwards  till I was popping down the exhaust. I would start it that way then bring the dist. (electronic)  advanced  to where it was starting to run OK then it would backfire and shut off. I do not have the outboard carbs hooked up if that could make a difference...just thought it may be easier to dial out any issues if I were just running off the center carb.  It also seemed that the carb was running out of gas also when it didn't backfire. New fuel pump also.  I am using  93 octane gas with  NO ETHANOL  in it.

   I do have a cast iron intake and a good 800  cfm. Carter to dial out  carb problems.  I did prime the oil pump and put in a bottle of Comp Cams brake in juice also.

   Any ideas ?

[sassygreen]

Take outboard carbs off and use flat blank piece of metal and seal off with silicon.

[Chryco Psycho]

it could be so many things , reluctor gap [should be .008] reversed wiring to the pick up coil in the dist , adavacne weights , carb issues , ballast resister  .....
 How hard is it to restart after , does it start right back up , do you have to pump[ the throttle or hold it open , do you have spark right after it quits  , is it flooded or starving for fuel ,  black smoke , air fuel or electrical , something has to be missing

[cudabob496]

back fire? timing issue, or plug wires crossed?

[HP_Cuda]

Check your plug wirings and that they are in the correct order:

www.mymopar.com/index.php?pid=27