I have a 350 with a TH350, and it shifts at about 2700 rpm. Reading other posts, most people seem to get into the 5000rpm range. Matter of fact, I can't get the car into the 3000+ rpm range at all. I had a friend look at it who is fairly knowledgeable, and he is stumpted too.

The car seems to pull ok on acceleration, but the motor just doesn't hit 3000. Also, even though the car pulls pretty good, you don't really feel the cars power band????

Here is what I know about the car, some of which is second hand info as I have only owned this car for about 6 weeks.

350 motor (w/ ported/polished heads per previous owner)
TH350 w/ shift kit (per previous owner)
600-650 Rochester 4 barrel carb
mild cam (previous owner doesnt remembers how big)
edelbrock alum intake
Hooker headers
stock 10 bolt, 3:08:01 gears

Any suggestions or explanations would be greatly appreciated!!

Greg

Are we talking shift points in drive? If so, the most obvious would be the kickdown cable. if it's not attached, or adjusted wrong, the trans will shift very early. #2 would be the hose to the vacaum modulator.

If we're talking you put it in low and it still shifts, past me....

Im no pro, but i think JimM is right. If its not the kickdown cable then you might have some tranny probs. What if you manly shift it?

The vacuum hose being off the modulator will make the tranny shift like it would at WOT all the time. THe kickdown cable does need to be hooked up. There could also be something wrong with the governor which under a round cap of the right rear side of the tranny.

Sounds like you need to connect a pressure guage to the tranny to see if if the kickdown and vacuum modulator and govenor circuits are working correctly. In general though, the THM350 is known for running too long in a gear. Most shiftkits that I have delt with make the THM350 shift early with the thought that if you want longer shifts you'll grab the handle. If the tranny and rear-end combo are mismatched, you may need to tweak the govenor.

Thanks for the help guys. I have some work ahead of me. Also, I didn't realize that the tranny would effect the RPM's so much.

67 camaroD: In regards to shifting the auto manually, the motor seems to be at its peak at about 3000. So thats when I shift it.

Another thing that is weird. When I let it shift on its own, it will chirp 2nd fairly easy. When I shift it manually it seems to hesitate a tad, does not shift hard( noticeably softer than when I let it shift on its own). I have just been chalking it up to the shift kit, but maybe not.

If anybody can think of other things for me to check please let me know.

Thanks again,
Greg

Hey guys from the research I've done, my 350 should not have a problem going to 5500 RPM, but mine won't go past 3000rpm. The kickdown cable isn't working as it wont downshift.

BUT... that wouldn't keep my engine from not reaching 5500rpm???

I am thinking that maybe its my carb. Maybe its not getting enough fuel?? Its a Rochester Quadrajet.
The only numbers I got off it is:
117054927
0747
These numbers were written vertically on the back driver side of the carb.

G

This trans problem, is it the trans or the engine won't go to 3000? If its engine, it could be timing, carb. (have someone get in and push the accelerator to the floor and check under hood to see if its getting Wide Open Throttle), Sound like you not getting throttle, make sure also none of your linkage is bent on the carb.

I have almost the same setup on my '68RS except a 327 and I have a new Edelbrock 650 carb. In drive mine shifts too early, not sure about RPM because I do not have a tach. If I manually shift she seems to hold the gear better but at times will still shift to second even though I have it in first. It will kick down gears with out a problem. It shift nice and firm and can get a nice chirp if the gear holds, which under harder acceleration it seems to do if shifted in first. Ok, so it shifts too early in drive and if I pull it down to first and don't stomp on it, it will shift to second without me shifting. Make sense?

If the linkage is adjusted right, and you put the shifter in first, it should stay in first, period, no matter what. If it won't go over 3000 rpm, there's something a lil screwy with the motor.
If the kickdown cable is not connected, it will shift very hard and very early if it's in drive, and will not automatically kick down in passing gear.
If the kickwodn cable is adjusted correctly, the governor and the vac modulator control when and how firn it shifts.

camaro fever68/maita---I'm beginning to think my problem is dist. or carb related. Here's the newest problem I've found regarding my carb.

One of my vacuum ports on my carb is not attached to anything. Also I believe that the two ports that do have vacuum lines on them are not attached to the right equipment.

This is the current set up (I have a Rochester-Quadrajet and a TH350):

--The lower front driver side port vacuum line goes to the Dist.
--The lower front passenger side port vacuum line goes to the choke
--The upper front passenger side port vacuum line has no line attached and is not plugged off.
--There is no vacuum line that goes from the carb to the tranny-TH350

Assuming my kickdown cable is properly hooked up, could these reasons be why my motor doesnt want to go past 3000 rpm, and the tranny doesnt want to down shift.

P.S. Can anybody tell me how and where these vacuum lines are supposed to go??

Greg

I'm no expert on q-jet vacaum ports, but, there 2 kinds, ported and unported.
Ported is not there at idle. put a gauge or your finger on it, at idle no sucky, bring the rpms up a lil, then got sucky sucky.
Unported is there all the time, put your finger on, fell sucky sucky.
There is a round thing that sticks out of the pass side of the trans. It must have a connection to UNPORTED vacaum.
The choke is on unported vacaum.
The distributor was originally on ported vacaum, but it may run better, idle smoother, and have better response on unported.
The stock air cleaner probably had a diverter valve in it to close off the snorkel and draw warm air from a tube to the exhaust manifold when it was cold, this went to unported vacaum.
There should not be anything unconnected. If you don't have a hose to put on it, get a cap and plug it.

I need to check out my linkage. It will not stay in first if the shifter is pulled into first. It does not shift hard at low RPM's. I also need to install a tach to see what is going on.
Thanks for the help!! :beers:

I need to check out my linkage. It will not stay in first if the shifter is pulled into first. It does not shift hard at low RPM's. I also need to install a tach to see what is going on.
Thanks for the help!! :beers:

Besides checking the tranny kickdown linkage,check some other stuff too.

Have a friend sit in the car,and {Unhook the battery}
have the friend push on the gas pedal,while you have the air cleaner off,
and with a Flashlight,{Not a lighter} ;)
you look to see if the throttle plates go straight up,fully open.

Alos check that with the air cleaner On that your gas pedal still moves the same.

I had a clogged gas filter a few years ago,and the car had No top end;
it ran fine for normal cruising,to go to work,etc... but no upper end.

Don't forget the simple stuff. :)