stalling out when put in gear

[71VERT]

I recently put a 670 cfm holley street avenger on my vet, It had a holley 750 cfm 3310-2 before it ran well but always ran rich fouling out the plugs. I replaced the valve stems seals also. After installing the carb It is not idleing correctly and as soon as I put it in gear it immediatley stalls. Any ideas ? I had the rockers on too tight initially and it wouldnt start but once I adjusted the lash It started but now stalls.

Thanks
Jerry

 

[cruzer99]

1. Is there a reason you didn't just re-jet your 750?
2. Bad idle = vaccume leak.
3. What is the idle set at in neutral?
4. What is the timming set at?
5. What did you set the valves at?
6. If you put the 750 back on does it idle OK?

 

[71VERT]

I didnt rejet the 750 because it was getting pretty old. My neighbor set the valves so I assume he knew what he was doing, He put his thumb over the empty spark plug hole and when he felt the compression he stopped and set the valve lash. The timing was fine before but I do not have a timing gun. I have not had time to put the old carb back on yet but that will be next.
What gets hooked up to the full manifold vacuum source on a 1971. There is a full manifold port, a pvc port, a power brake port and a timed spark vacuum source. Sorry I do not know alot about the vacuum system.

Thanks
Jerry