[hotrod]

Sounds like a mixture distribution problem. I'd switch to straight water and see what it does. You may need to run multiple jets to get an even distribution.

It will probably take some experimentation to figure things out.

If your using a single jet in front, you may want to switch to 2 jets one on each side near the rear of the primaries.

The other option would be to pull the manifold and carburator and have it flow tested by some one with a flow bench.

You might have to use multiple EGT gauges to figure out what is happening.

You might try running it up to the point it starts to spray and cutting the engine while its spraying and then pulling the carburator (if you can) and see if you can see a big difference in how wet the manifold runners are.

Not much help I know but you'll just need to do some tests to figure out what is going on.

Larry