30 degrees total? = Too low.
You need a distributer advance curve kit, SBC works. More performance, better mileage.
When you say a back fire,,, out of the carb?
Accelerator squirt not doing it's job ?
MBHD
Soooo, what you're telling me is I need new HEI? Twist my arm. 30 degrees was all mechanical, no vacuum, but it's lower than what others get. Maybe I didn't rev it high enough. But it could just be 48 years old and tired... Yes, the backfire sounds through the carb. I'm pretty sure it still is, it was definite before I started taking the timing forward (witnessed the flames).
I don't know much about carbs, but am learning. The accelerator pump seems to work just fine. It seems that the problem I have is with just slight throttle. If I press harder, get to the point where the squirters do their job, no problems. It could be as simple as too much carb (390 CFM) for a stock 230. When I'm driving along, 45-55 MPH, it seems I hardly have to hit the gas at all to maintain. But there's no torque or staying power. The hesitation was getting annoying the other day. I might open the idle adjustment screws a bit to see if that helps. I'm not going to change the jets before the overhaul.
Mark
