[RD31]

Do some more research, perhaps on the other forums as well. I've read many threads where someone has tried to convert to EFI and had tons of issues. If you get it right it can be great, but sometimes it just doesn't every get there. My engine builder kept me away from EFI. I suspect the 850 cfm carb may be oversized for how you are using the car. I run a 750 cfm carb with a 408 pushing just short of 600 hp. With a good tune a carb will perform well. I've used the Air fuel ratio systems and they can help a lot as well. Like Tommy said, try a professional tuner perhaps before taking the plunge.