LM7 5.3 with 700R4 - can't get the transmission to shift right

[paradigm]

I welded a TV carb bracket onto the throttle body cable arm of my 5.3 LM7 to connect the TV cable of my 700R4 to the throttle body to get the transmission to shift in my '86 Monte Carlo SS. If I change the angle and add tension to the TV cable to throttle body, the transmission shifts at a higher RPM, and kicks down better, however under WOT it stays redlined in 2nd gear. Under normal throttle it sticks to 3rd gear on the highway and doesn't shift into 4th.

With less tension on the TV cable and different angle to the TB cable arm, the car shifts crisply at lower rpms however it doesn't kick down under WOT and just picks up speed in the same gear you attempt to go WOT in. Also on the highway it seems to top out in 3rd gear.

The car just isn't shifting like it should because of this TV cable to LS motor incapability. Only one aftermarket kit appears to possible solve the issue from Bowtie Overdrives - has anyone here had luck with it?

I am thinking I should either:

A) invest in a $350 in a bowtie overdrives TV cable adapter kit - again has anyone used it and had good results? https://www.bowtieoverdrives.com/cat...php?ITEMID=373

B) swap out my 700R4 for a 4L60 or 4L80 - not sure how much that would cost, and how labor intensive that is but seems like this will cost me at least $1k parts and labor or more.

C) keep screwing around with my throttle body to TV cable setup. Ill likely never get it right, or is there some good knowledge out there to DIY and set it up correctly?

Thoughts on how to get this transmission shifting properly?

TV cable to throttle body below:

Bowtie Overdrives kit:

Engine Bay:

 

[nycutlass]

in my opinion i would do the 4L80E for your 5.3 LS swap do it once and forget about it . you just did a quantum leap forward with the LS 5.3 and then went back in time of the horse and buggy with the 700r4. if the 4L80E is not obtainable for any reason then just go with the 4L60E. the computer most likely is already set for a 4L60E. but its super simple to the 4L80E as well with the same computer

 

[stew86MCSS396]

If you decide to keep messin' with the 700r4, try searching 700r4+geometry and compare the results to what you find. My understanding is it needs to be precise and not "close enough," well at least within spec.

 

[nycutlass]

you cant play around with the TV cable "to figure it out". you wont make it 6 feet and blow the whole trans up. Even GM couldn't get it completely right and got rid of the design.

 

[paradigm]

you cant play around with the TV cable "to figure it out". you wont make it 6 feet and blow the whole trans up. Even GM couldn't get it completely right and got rid of the design.

I’ve been messing around with the TV cable now for like 100 miles and going wide open with it. The prior owner drove the car without the TV cable connected probably another 50 miles, manually shifting it. The transmission fluid looks bright red. I wonder how damaged the transmission is from all of this?

Either way at it sounds like I’ll never get the cable properly aligned unless I perhaps use the Bowtie overdrive’s kit.

I think a 4L60 or 4L80 is the way to do, but I want to keep costs down by doing the swap myself with a helping hand. Problem is that I’ve never done a transmission or motor swap before.

 

[nycutlass]

The prior owner drove the car without the TV cable connected probably another 50 miles, manually shifting it. The transmission fluid looks bright red. I wonder how damaged the transmission is from all of this?

that is impossible ! i do not believe one word of that I'm sorry, that cable controls the shift points and line pressure within an automatic transmission lol....... without it being connected you leaving in drive simple as that !!!!!!!!!

 

[paradigm]

that is impossible ! i do not believe one word of that I'm sorry, that cable controls the pressure of the pump lol

I know it sounds ridiculous, but I saw the previous owner manage to manually shift up with the transmission manually without the TV cable connected by moving the gear selector down.

 

[nycutlass]

I know it sounds ridiculous, but I saw the previous owner manage to manually shift up with the transmission manually without the TV cable connected by moving the gear selector down.

miracles do happen i guess all over the world. either way i done a LS swap ( I love it ), and the way to go is TH400, TH350, 4L60E, 4L80E or manual trans. your computer most likely has already a 4L60E tune send me your BIN file let me see what is going on if you don't mind your using a PO1 computer correct?

 

[paradigm]

miracles do happen i guess all over the world. either way i done a LS swap ( I love it ), and the way to go is TH400, TH350, 4L60E, 4L80E or manual trans. your computer most likely has already a 4L60E tune send me your BIN file let me see what is going on if you don't mind your using a PO1 computer correct?

I never gone the BIN file, the prior owner got a base tune and PCM from PSI conversions. I will ask PSI conversions for the BIN file and then I can send it to you, or I should get a dongle and software to download it myself?

As for the PCM I believe it is a P01 as the engine was originally from a 99 Silverado.

 

[nycutlass]

depending how far you want to go with this, maybe at the least to start is getting a dongle is best for starters. you can get stock tunes all over if that is what you have going on. i don't have any more details on your project to tell you any more.