Dart falls on it's face.

1wild&crazyguy said
not to side track but we both know that carb is too small if you've up'd the jets 5 sizes.
you are running pv's , explains the 74's across, otherwise 82 secondary.

I don't think his 256* cam'd 318 is gonna pull that 600 very hard.

he may be fine with the jets, but has he done any vacuum checking and have the correct pv installed?

I would keep the jets no more 9 sizes apart, so find out what secondary plate you have to convert the # to jet#'s and see if you are too fat on the secondary side, along with timing...find out when [rpm] the full advance comes in.

just a drunkin ponder.

You are correct in that the carb (650 dp) and the manifold (Weiand Action+) are too small. How do I know? First I added a 1" open spacer and felt a huge gain from 2500 rpm on up with no effect in off idle performance. Then I added another 1/2" open spacer and felt more gains. Not just a little 10hp kick but literally it felt like a 40hp difference.

This engine begs for an eddy rpm performer and a 750. It'll buck and snort with anything less than 74's in the primaries (in this cool weather) in the mid range and the plugs will run dead white and not color at all. I'm running a 6.5 primary PV and there is no provision for a secondary PV on the metering block (it's list number 4777). At first I tried the jet stagger and it wouldn't run past 5-5.2K and it would pop and snap through the exhaust, almost like hitting a rev limter (yes, I checked, mine was set at 6k) or valve float. This was hard to check on public roads for obvious reasons, but I found a couple of good, long entrance ramps to, ah, road test on. I had to keep dropping the secondary jets until it reved clean. In the summer I have to drop the secondaries to 71 or 72 and primaries to 73. Why the wierd stagger? From watching the plugs, I think that fuel distrubution sucks on that Weiand, that's my best guess.

Keep in mind that I wasn't suggesting that he start that big, just that he may not need to drop the jets so far just due to altitude. If I were him I'd start with 68's, test ride and check plugs, rinse, repeat. :read2: