prostreet1972

I have a sbc 350 stock bore and bottom end in my 72 chevelle. Double hump heads ported to match the team G intake. 750DP. Lunati bracket master II solid lift cam (part #00013). It's .500/.515. lift and 256/270 duration @.050. I had to up the jets quite a bit 80/86 with 4.5 powervalve. I have an air/fuel ratio gauge and still says a little on the lean side. I know my fuel pressure is right.

I cannot get this thing to idle below 1200rpm and my total timing is almost 50 advance. If I retard the timing at all it starts backfiring out the carb like crazy. my vacumm is about 5in at idle. With timing like this, it seems to run great, great throttle response and sounds really healthy. This is with no load, I haven't been able to get to the track to test it out.

I have checked for vacumm leaks, none found. Could it be leaking between the intake ports or into the lifter valley? The wall between the intake ports are pretty thin, and I didn't like the way the gaskets were sitting when I put the intake on. Motor doesn't smoke.

I installed the cam straight up (atleast the best I could). I am using a gear drive and it didn't seem like I could get the dots on the gears perfectly inline. Could the cam be installed incorrectly and throw off my timing?

I don't feel that it is a carb. problem, but I am open to any suggestions. I am honestly out of ideas...

Thanks,

Travis