This is not a chevy engine, yeah yeah, i know. it is a pontiac 400 in a 71 camaro. I don't know if your familiar with pontiac engines but i wil give it a try. it has msd distribitor, 6A box, and coil, it has a holley 4150 double pumper 650, I have the floats maybe just a little to high in the sight plug, i can see the gas about 1/4 filled. the idle adjustment screws are about about 2 turns. I just put in some autolite plugs that are colder, since i posted, they are #5, they were #6 it seems to run a little smoother but are still bright white, today i am going to try to change the jets, see if it does anything, also it does just hesitate, or stutter, just barely when i hold it at about3500 rpm, but if i hit the gas it runs fine, anymore information would be great. oh yeah i heard that vaccuum leaks at the intake would do it but i sprayed carb. cleaner around and it had no affect.