Carburetor and Ignition Help Needed

[zorin]

After losing my 3.0L engine (broken rod), I replaced it with a 3.2 L engine. I am still using Zenith carbs (28 mm venturies) that was used on the 3.0 engine. Basically everything including ignition coil, fuel pump, carburetor venturies and jets are the same except for the engine, and the distributor. The engine runs but not great. I have less power than with 3.0 L engine, at idle cylinders 1 and 5 do not seem to deliver, there is backfire at around 3000 to 4000 RPM, spark plugs get carbon deposit after few miles of driving , etc. My guess is that the venturis sizes and the jets are too small . I am not sure if I need to get a special ignition coil for the new setup.
What changes do I need to make to have the engine running/idling smooth, short of replacing the carbs with PMO ones?
How can I tell what size jets I am using?
Is there a special ignition coil I should use i.e. MDS?


Thanks

[RoninLB]

your engine needs to be dialed in

either find a 3.2 carb pelicanhead for advise [search] or take it to someone who has experience

I use the MSD and MSD coil. Many posts on MSD coils.

it'll be a great engine when finished

[James Brown]

contact pcar9119@yahoo.com for the correct vents (34-36) for that size engine, he makes custom ones for Zeniths! main jets should be around 160-170 idle around 65. solex jets fit nice.
Ignition system is ok just needs to be recurved for carbs

[zorin]

Thanks guys.