hey, i just put a th350 in my 84 camaro, i didn't have tranny or engine when i bought the car, it did use to have a th350 for tranny, what i want to know is do i need the i think its called tv cable one that goes to the carb? Thats for the shift points aye? or is it just for a passing gear, if i don't use it what will it do? haven't gotten the chance to drive the car yet, that why i am asking and also what cable should i use if i do need one, cause i did not get any with tranny or car. Will it still work if i say **** it manually, like go from 1 to 2 to d?

 

correct me if im wrong...i think the tv cable is only on the 700r4...a th350 should have a vaccuum line that hooks up to the back of the intake

 

yes i seen that, do i need this vacuum line?,

 

Yes you MUST have the vacuum line.

You don't "need" the cable, however; all it does in a 350, is provide automatic kickdown when you floor it. The vacuum system does the equivalent thing that the TV cable does in a 700, which is to tell the transmission what kind of load the engine is under so that the trans can make the right decisions about when and how to shift.

 

ok thanks, so no tv cable, just the vacuum line?, i noticed my dad had that on his truck, didn't know if needed it or not. And as for tv cable, it won't downshift when i floor it now aye? i plan on putting shift kit in anyways so it won't matter if i just slam it in second when i floor it aye?

 

You need the vacuum line on the TH350. It provides a signal to the modulator to allow upshifts. Without it, the tranny will only upshift when the governor peaks so it won't do any part throttle upshifts.

The TH350 cable isn't a TV cable but works roughly the same way. It's called the detent cable. Without it, when you push down on the accelerator, the tranny won't know to downshift.

 

I remember lots of guys back in the day who just manually downshifted their TH350's because of a broken or misadjusted kickdown cable. So yeah, the kickdown cable isn't a necessity, but it does make it nicer when you want passing gear, since you just floor it, and it downshifts automatically. As Sofa said, the vacuum line is a must have. Without it, the trans won't shift until about 5K or higher, and when it does shift, it's hard enough to break something. Had the vacuum line come off on my old 77 Camaro a couple of times. The downside to a TH350 is the lack of an overdrive, but the upside is they're tough as nails compared to the 700r4. I had a small block 400 in front of the one in my 77. I never did anything to the trans other than make sure the fluid was topped off, and it never gave me any problems. I used to powerbrake it standing still from 1st gear all the way into drive while frying the hell outta the tires. Man that used to be fun!

 

Not trying to hijack the thread, but I have a question about the modulator.

If it is an adjustable one, which way do you turn the internal screw. If the shifts are early, do you go left or right?

 

hehe powerbrake, the one thing a rice burner can't do haha!, but as for performance comparing the 700r4 to th350, say in a 1/4 mile run same car and engine, would any one of them do a better time or both similar? Like are is the gearing pretty much the same from 1-3 on 700r4 as it is from 1-D on a th350?

 

You should definitely make sure to get the carb linkage hooked to your tranny so that overdrive can be used. Basically, when you hit your gas hard you won't downshift, which isn't a big problem unless you need to pass.

The vacuum line needs to be there for sure or you're not going to be getting smooth shifts, or shifts at all.

 

Actually, the 700r4 has the advantage coming out of the hole because 1st gear is lower (3.06:1), whereas the TH350's 1st gear is 2.52:1. However, the TH350's 3 gears are spread out more evenly, so they're said to be better for racing as long as you have a steep enough rearend gear and a good stall to compensate for the 2.52 1st gear. The 700r4 has a bigger drop in rpms when it shifts from 1st to 2nd, so you can lose a little more momentum if it drops your motor's rpms below its peak power range.

 

That was one of the main reasons I switched to the TH350. That 1-2 shift can just kill your rpm.

Also, the TH350 is lighter than the 700R4.