A plane Jane 350 cutless single exhaust, two barrel ,273 peg leg were not a performance vehicle. sorry boy and girls back when muscle car were new a stock big block car that could brake into the 13 were not the norm. Performance cars of the late 60 and early 70 ran in the 14 and 15 second quarter mile show room stock form. Even some of the advertised time were done with a ringer that the manufacturer work over with there engineers .

As with anything with some tweeking and traction assistance any car could be improved on.

You guys have me thinking of some real old school tweaking that was common.like removing one spring on the distributor counter weight.locking out the distributor.open element air filter.glass packs or gutting out a turbo muffler.Vega converters.blocking the accumulator in the trans.removing the seal on the back of the hood to suck out the hot air.removing the PS belt.overfilling the front tires. Slapper bars. Remove weight.well there more of them but this is just a few off the top of my head some of them worked.

 

I never said anything about running a 13 second ET. What I disagreed with about your post, and I made it VERY clear, was that you should not have included 1970 models in your statement. Compression ratios were higher and the cars more powerful. Yes, I agree that the 71-72 350s were pretty weak with their 8 to 1 CRs, just clarifying that it was NOT the case in 1970. Also, the main issue with most of the posted ETs back in the day were the bias ply tires. Bolt a pair of Mickey Stickies on almost any big block muscle car of that era and you are running a low 14/high 13, IMHO.

 

Please folks, stop arguing. It is not against any guidelines and nobody has flamed anyone else (thank you) but I don't think arguing or "calling out" somebody's statements about performance is going to help in this case. I don't even think the OP is even reading this any more, at least I hope not; he hasn't posted recently. Everyone has said their say so let it be.

 

In the 70 model year there were only about 1200 give or take w 31 made, those ran well. Even with a little better compression all others were just the same old 350 smooth cam engine. Power between thouse engine with different option's was small .you kids are funny you think going from a two barrel to a four barral there is a big power jump .there is some power but not as much as guys think.a retrictive exhaust and a camshafts with conservative valve timeing were not hurting for more air flow.

 

Years ago in a sweet and simple way I was told. "You wanna make power with a small block you need cam , compression and gear". In the most simple way that's wha you need. Now we all know there is more to it but its sweet and short . Now the only voodoo trick I did was put an x pipe on and I almost picked up 2 tenths. Although some would argue that I have the time slips to prove it picked the 2 tenths from the x pipe. Of course tossing a belt was always worth a tenth . That always happened by mistake.

 

This is crazy. I bought a 1405 and i've put bigger secondaries in it, and increased it on the chart for 8%(3 steps) rich and it still hesitates or bogs sometimes.

There's gotta be something else wrong. It's not a race car, and there is no way in hell it'll run anywhere near 13.2 in the 1/4 like yours. It shouldn't need this much gas, 3.23 gears aren't high enough to justify it.

Clear fuel filter looks clean, and only put in about 2500 miles ago, maybe I'll change it out, when I test the fuel pressure, before and after. Something is changing. Sometimes it runs okay, other days, not so much.

 

Well in my experience the 1405 in my dads car has too much initial fuel delivery . I still need to put in lighter springs to bring the timing in faster as I tuned it for 2.41 gears (no joke ) but it has a slight hesitation . The diffrence between when that engine was in my car and my dads is a much more free flowing exhaust. I had full length headers (which will lean and engine out ) and an x pipe with hooker aero chambers. My dads car had manifolds and smaller pipes and turbo thrush mufflers. All in al its a very slight hesitation but we are doing a q jet for it as the 1405 is a gas pig and I would like my dad to get better mpg. I also experience the one day it runs good and the next it sucks. Those carbs gunk up real easy with todays fuel. I'm just not messing with the one we have because we have chosen to go qjet. The particular engine that was in my car then my dads was a mild 9 to 1 set up with a towing cam stock 72 7a heads and stock 73 350 short block nothing real special there. That set up ran 13.86 through the mufflers. My 13.3 350 set up had 10 to 1 compression , rpm intake bigger cam comp 280h , big valved heads. I ran the 1405 on both those engines. Once I choked the mild set up wit stock style exhaust the 1405 started to be too much for it.

 

Wait a minute, with stock manifolds/exhaust and the slightly hopped up motor on a 1405 carb out of the box and the carb was too much!? Hmm.. My car is a stock 72, best I can tell original or stock rebuild, idles with 19in vacuum, 7a heads, HEI ignition out of a newer GM wth 16* initial, about 36-38* all in at 3000rpms, 3.23 rear end gears. Stock manifolds, I think 2 1/4 exhaust through Dynomax mufflers. Nothing crazy by any means. But if I'm going up an incline at WOT, it feels like I run out of fuel, it goes nice, winds up to like 4000 hits like a wall for .5 seconds and feels as if I let of the gas, then comes back to life.

This is really interesting. Maybe I'm getting too much initially. Whats the difference feel like between too lean and too rich? My plugs look on the leaner side, they're light light brown, not black like rich would indicate.

 

Your idle will be fine as is mine since its on the idle circuits . Its the transitioning between idle and power mode that needs to be better tuned. The edelbrocks are a pain the @$$ to tune. I could be lean it or could need more fuel off the line or less you need to go up or down to really see what it likes . Considering I choked it back and put the engine in a heavier car im on the rich side of things and my plugs are slightly reading rich. if you are having a stumble from idle to "power mode" then its the transition between those 2 fuel metering circuits. have you tried messing with the pump shot settings ?

 

I've experienced this in my Cutlass. After an hour and a half at 80mph on the highway coming back from a Connecticut car show, I noticed at the first red light it seemed slower. My car does run a little hot, maybe 205/210 the most doing 80. Slow down to 70 its right on 195. It never goes above 210, 90* day in traffic, right on 210. Maybe my car would benefit from a 180* thermostat, or a 4 core radiator, but the T-Stat is a lot easier.

But I've already got one of the open air element breathers, a WIX flter with the Chrome Edelbrock Cover. So I can't comment on that, I don't know what it was like with a snorkel.

Copper:

I noticed the 1405 is kind of a pig myself. I'm hesitant to rebuild the Q-Jet, guys on here with rebuilt Q-jets need to readjust them because of an exhuast. The same guy who built his carb told me he'd rebuild mine to stock and it would be find for my dual exhaust, that seems like it'd be back to square 1 with a Q-Jet after it's done.

It seemed like going to step 10 (rich on power and cruise mode) seemed to help my car, and my last though it to try one more stage rich on cruise to step 15.

How does one calibrate the idle-power transition? The pump shot adjustment does nothing. I even bought a new accelertor pump. From the top hole, to the middle hole, to the bottom hole, I really don't notice a difference. Maybe slightly less umph if it in the top hole than the middle, hard to tell.

 

The pump shot helped on my dads car a lot. Its been a while since I messed with an edlebrock but I usually followed the chart because the edlebrock is based on an o.e.m carb so it was design to work all across the board so if you make one change chances are you need to make other changes. I went to a holley on my car years back and I may have one last crack at my dads car with the edelbrock . Have you messed with the timing at all ? Have you tried to bring the timing in sooner ? I know on my dads car the timing is coming in really slow due to the springs I put in the distributor to aid it's driveability with the 2.41 rear gear. Im changing that and its very noticeable while im driving when the timing is coming in. I also know it needs more timing sooner because when I had a lot of initial it ran a lot better. This may not be your fix but im throwing the possibility out there just from my experience.

 

1405 are set a little fat for people that upgrade to headders and good exhaust. On the primary's there usually close.you should try to go leaner not richer. If it too lean they have hestation. If it too rich it will act slugest. Since moving the pump arm has no effect it is more likely rich. If your engine has high vacume try the higher vacume metering rod springs when you go leaner jet rod .then on heavy part throttle it will start to enrich sooner cleaning up some of the transition.

As for the idle circuit it has idle fuel restriction and idle air bleeds . on a stock engine you could enlarge the air bleed a little but it also change the timeing on when it transition from idle to mains. Kind of risky to me.I would try instead put the vacume advance to manifold to tighten up the idle transfer slot so you can lean out the idle screws a little.

The biggest problem with them carburators is the non adjustable secondarys.they cause havoc opening to soon or too late . that when people have the problems with that carb .a stumble then goes like hell it starting to early making a lean spot.too late it fells kind of flat when it come in too late.