6 in a row makes it go? But at 5k ft elevation?

[mattbert56]

Well I'm sure there are many threads of carb stuff for inlines, but wondering if anyone that lives in higher elevations has any input. I've got a 1406 edelbrock on an offy intake and long downtime headers. Stock cam. .20 overbore. Rest of the engine is stock. I cannot seem to lean it out enough for it to run reliably, being at 5k foot and only seeming to drive it in higher elevations. (The mountains) I'm wondering if downsizing the jets to the sizing of an edelbrock 500 would be beneficial? About 70 bucks give or take, or switching to a 390 Holley? The carb that's on it really has treated me well up till now. Little situation backstory. Truck was moved from sea level fo where I live now in Wyoming. Different air. Thinner. Ha less of it. Any input would be rad. Thanks.