Running rough

[rpmerf]

I think I will be pulling the intake at some point. It's my DD right now (not like I'm driving daily anyway), and I'm wondering if my time would be better spent trying to get my Suburban's front suspension back together. At least I know what to expect there. It's possible I could pull the intake on the C20, and it doesn't make a difference.

If I'm pulling this intake off, I almost want to drop an aluminum intake on, but I don't want to introduce any new variables. Same with installing the HEI I've had on the shelf for a couple years now.

[rpmerf]

Drove it today. Around 45* out. Started it up and it's running bad again. About 3/4 of a mile in, I'm going up a hill and struggling to do 35 mph at WOT. Choke still on, so no secondaries. I think the AFR was in the 14s. Choke and full enrichment normally should have the AFR in the 10s. Still, AFR in the 14s should run OK. I'm WOT for about 5 seconds and it starts running better like I flipped a switch. Engine sound changed, so I let off a bit and the AFR went into the mid 12s, which is normal when the choke is on. Ran great the rest of the way there and back, about 5 miles each way.

[mattfranklin]

Sometimes when things get really weird it's two or more things that have gone wrong.

I don't mean to be critical or nitpick, I'm just thinking through the possibilities...

When you had the top off was the gasket 100% ok?
Did it all go back together well with all of the screws in the right holes and tightened?
If you change that spring back to the original does it get better?

Is there a hidden vacuum hose under the carb that is cracked or disconnected?
When was the last time you changed your points and condenser?

When you run it at night with the hood open do you see any sparks?