I recently swapped out my 305 with a 350 (.060 over) and mild cam stock intake and a older quadrajet with mechanical choke recently rebuilt. HEI distributor with vacuum advance. I turn the distributor as far advance as possible without it kicking back against the starter, it starts fine and runs pretty good at idle.
The throttle response is weak from idle but good from 1500+
When i advance the distributor it seems to idle and rev better without pinging. But when I cut the engine off and try to start again its kicking back against the starter and just turns over very slowly like its to far advance
Do i need to adjust the vacuum canister or change my springs?

 

Have you tried setting the timing the correct way with a timing light instead of guessing ?

 

Get a stop and verify true tdc. Then once its established that its correct, disconnect your vacuum advance and plug it at the Carb. Get some advance in it and get it started, set your initial around 16° -18° then set your idle at that point. Bring it up and watch your light. Assuming its a stock HEI you should see around 36° around 3000rpm. If this is what you get, drive the car and see how it feels. If your battery is good and your grounds are good you should have no issue starting and it should run fine. You can the tailor your springs and weights for more or less total, and when it all comes in. The same with your vacuum advance, ported or manifold, when and how much etc. That will all be feel depending on cam and compression and the heads efficiency. But at least this will get you close and if there are further drivability issues then you have other problems, dist off a tooth, or cam installed wrong etc.....

 

Problem is he makes no mention of using a timing light ;
all he appears to be doing is just screwing around blindly with the dist trying to find " somewhere" were it runs "right"

 

The problem with "using a timing light" is, all it can tell you, is where the timing is; it can't tell you where it should be. "looking up" some "spec" based on your vehicle's sheet metal wrinkles in some "book" will only tell you what it should be if the engine is absolutely untouched and identical to how it left the factory; once it's been modified, the owner must learn where it now should be instead of the "spec", which is now, by definition, WRONG. Easiest way to get there, is:

"If it RUNS good, it IS good".

If the starter is too weak to start the engine when it RUNS good, then maybe the problem is THE STARTER, not THE ENGINE.

 

Ah yes lol....I hadn't noticed. I still know guys that do this, even after spending money on good parts.....but not a good dial back light.....well, to the OP, if you have one, follow my steps and use it, if you don't, stop chasing your tail until you get one.

 

Modified yes, which is why I used a fairly standard 16-18° instead of 8. "If it runs good it is good" is so vague and possibly detrimental, how many motors run their best loose and on their way out? How good is "good" till one tank of junk gas makes it eat itself.....and if it was just a "slow roll" then I would likely be chasing starter or wiring issues, but the fact that he said it "kicks back" leads me to belive there's something else going on. I still stand by my "get a friggen light man" advice. I suspect that he is going to get the timing dialed in correctly and at that point, if its still lazy he can then find the real issue as oposed to it being masked with a ton of timing that it likely has now.

 

I miss placed my timing light, or borrowed it out and never got it back. I have never had a problem without using one before untill now :/. Ill buy one this weekend and try the steps above, thanks for the feedback everyone. Could the problem be its a cheap aftermarket hei unit? I installed it in the original 305 and it ran pretty well but sitting for a few months and being moved around change its performance?

Also my alternator is in good working condition, I have load tested the battery and its in good shape. The starter is pretty new and i had it tested like a week ago before installing, But it is stock replacement and the 305 had like 8.5:1 compression and I'm now estimating 10.3+:1 compression