1500 Spit w/ SU carburation

[Chris Crisenbery <ffajackson@absolute-net.com>]

Hey list need some help,

Buddy of mine is installing  1 1/4 " SU's on his 77' Spit and we cant
seem to get it to run. Here is what we know: need to choke to keep it
running
                                    appears to run rich
                                    idles at 1500 stalls below
                                    runs well between 4000-6000 rpms
                                    backfires thru carbs
                                    poor power
                                    no markings on needles
                                    electric fuel pump 2-4 psi
                                    pressure regulator set at 2 psi

Has anyone done this conversion?
what needles are you running?
jet height? diameter .090 or .100 dia.
Timing of engine?
float setting?
general suggestions

Look forward to everyones suggestions.

Chris