I am new to this site, but have worked on and mofidified carburated cars a long time so please bare with me. This is actually the first computer controlled modification I have done. I have an '87 GTA 350 tpi. It has 30lb injectors,SLP runners,T/F heads,headers,comp cam,ported plenum,custom Ed Wright prom, forged pistons, 700r4 w/ B/M 2500 rpm stall conv,etc...I have been running this combo for 3 years and would like to remove the TPI setup and replace with a carb setup. Is this possible while keeping the 700r4 trans in the car?? I have had many problems of late with fuel delivery and sensor failures. Let me know if this swap is possible with that electronic trans in there and what exactly needs to be disconnected,eliminated, changed etc to accomodate a carb setup. Thanks...

 

You should not have any problems swapping to carb with a 700r4. The only thing you may have to deal with depending on the year is how the lockup on the converter is controlled. My car came with a carb from the factory so it has a vacuum switch that activates the lockup on the converter. You can buy these kits on Jegs.

You will need a vacuum advance distributor to replace your computer controlled one as well as an intake. It is not a hard swap to do.

Most of all, do what you want to do with your car because someone will come on this post and try to convince you not to do this swap.

 

Does this vacuum switch directly replace the electronic lockup?? All I really know about the trans is that there is an electrical connector with wires on the side of it. Does the converter need changed too?? It's a lockup style converter. Thanks.

 

Your converter is fine if it is a lockup style. Here's a link to the part. You will recognize the 4 pronged connector in the picture.


http://www.jegs.com/cgi-bin/ncommerc...22&prmenbr=361

There's many companies that make them for various prices and some setups are slightly different, but that's closest to what my 84 TA came with from the factory. You probably have a similar preasure sensor in your trans already as well has the switch for the brake pedal.

 

Thanks for your research. I checked with TPI specialties and they also offer a kit that does not require any vacuum solenoids or anything like that. Their kit is only $69 and you don't have to pull the pan or anything. It also locks up the conv. in 4th gear. Anything else on the motor that might need swapped?? I already have the intake and carb and I guess I will probably need a different distributor??? I have an older Mallory unilite I will probably run with the Crane ignition I already have installed. I have the T/F 23 degree heads on there now. I read somewhere about the center intake manifold bolt holes being at a different angle on the TPI manifold as compared to the Edelbrock intake I am going to run. Is that accurate and do they make some sort of wedge shaped washer to accomodate that intake to those heads??? That's about all I can think of...Let me know if I have overlooked anything and thanks again for your help...

 

That's great if there's another way to do the lockup. Whatever is easiest and most cost effective I'd say. You will need a vacuum advance distributor also as you said. As far as the center bolt holes, you can elongate them a bit so the bolts will go in with no problems. You don't have to use special washers or anything.

 

you dont have to do the lock up switch if you keep the computer. the computer will only be controlling the lockup, can disconnect everything else running to it. it doesnt run the guages or anything like that. a lot of people ask that so i figured id answer incase you were wondering. when you go to carb, you can ditch everything under the hood. just make sure you keep the links and the wiring to the horn and things youll need etc.. i took the whole harnness off the passanger side of the car, MUCH cleaner under there now. im currently in the process of getting my hands on an AC delete box. also, if you want to keep the fan on the relay, make sure you dont ditch that wiring too. i went crazy tearing out wires i wasnt sure of before knowing what they actually did and ended up taking out the fan relays and such. now i run everything off a switch board. still trying to get my heat to work. have no idea on the 3 wires i have left sticking out of the box...

also, you cannot use the TPI fuel pump with a carb. too much psi. ive heard of people using the stock pump and running a reg to controll the flow. i just ran a new pump through stainless braided lines. i did a total tear down and rebuild on the whole car. make sure you get a correct bracket for the tv line too. carbs can abnormaly wear out the 700s if the line isnt adjusted properly with the correct bracket

 

who sels that bracket, any links....

 

He is right about keeping the computer. I was speaking from the standpoint of stripping everything out as far as the computer goes. I left my computer in as well to make sure not to have any unforseen problems though the engine does not use anything computer related.

Performance Automotive and Transmission Center Carries the Brackets for the kickdown cable and many other trans parts. Thats where I got my rebuild kit when I did my trans.

http://www.transmissioncenter.net/

 

Thanks for all the input. I was going to install the TPI lockup bypass kit and disconnect the fuel injection and distributor. I was going to run a Mallory unilite in place of the HEI. I was also going to leave the temp sending units and the fans connected. Will the fans still activate at 160 degrees because that's what is programmed on the chip???

 

the fans will work as long as you dont screw wit hthe relays and switch. i dont think they are wired into the computer, just a sensor that triggers the switch. i could be wrong. like i said before, i like tearing EVERYTHING out and starting from scratch. i think its the best way to do things. upgrading the distributer is a good idea. id get an MSD box also. i got the whole MSD setup in my swap. mounted it right in the center console to avoid damp/hot conditions

 

The best way would be to leave the computer in like you are already planning. The fans on the later fbodies do run through the computer. Everything else sounds to be pretty good. You could get an ignition box but you won't see a significant improvement.

 

Thanks a lot guys. I am already running a Crane HI-6S ignition coil and box. The box has a two stage rev limiter and boost retard because I was, at some point, planning on adding a supercharger. Thanks again for all your help. I plan on starting on this project next week and if all goes well, I may put the old setup, injectors,runners and intake on ebay or something. Thanks again.