Problems with Howell chip

[KasaRyan at aol.com]

Hi there, I am having problems getting at least near-carbureted driveability 
on a Howell setup on my truck.  I believe the system is totally sound, but 
there seem to be big discontinuities in the fuel curves of the chips, am also 
having a problem with being way too rich at times.

In a 93 chevy pickup with a 4L60E trans, and 3.42 gear
I am using a 1994 ECM - because they said I had to - I don't know why.
I built a 383 with 9.6:1 cr, 218/226 .454/.480 cam 112LSA.
Edelbrock 6085 Al heads, JBA headers, no cat, 3" gibson exhaust,
Holley 700cfm four barrel TBI on holley dual plane street dominator manifold 
w/egr

Is there anyone better at burning chips for such modified applications than 
Howell?  I have gone thru 4 iterations and am still displeased.  I have a 
autoxray scantool and can give results of chip changes.  If I had a way of 
checking, changing, and burning chips myself I would do it, but I bought a 
package deal, and it's not quite what I expected.

I can also post scantool results at various rpm and problem areas if anyone 
is interested.  Someone please help.  I have enough motor here to make 400+ 
HP, but I don't think i'm anywhere close, and I'm getting only 15mpg.

Thanks
kasaryan at aol.com