Hello.
I am planning on swapping my 305 for a 350.
My z came carburated,
So does anyone know if i need to buy the torque converter lockout plug?
And if so whats wrong with the set up i currently have.
Is that plug needed because the new carb i bought is set up to mate with the gen 1 smallblock setup?
I have a friend doing the swap and we both dont know were to tie the plug into
I apologize for the long post and any help is appreciated.
Thank you

 

Are you using the same carb when you do the swap? Is it the factory q-jet carb?

 

Do you mean torque converter lockout plug as in the wiring connector? If so well, not hooking up the trans lock out wire won't damage your transmission. I'm not sure if you if you will get a service light because I have the TPI system.
If you leave the trans lock unhooked you will have less fuel economy on the highway. Some people will tell you will generate more heat in your transmission at highway speeds. Which is true but your transmission cooler can handle that little increase in heat no problem.
I'm not sure how strong of a 350 you are putting in. If you are putting 325 HP or more I strongly suggest to send you transmission to a performance transmission shop and get rid of the stock paper friction plates because your transmission won't last long if you drive it hard. Switch out to like Red Eagle friction plates or some other friction material other than paper and at that time just have the shop convert your transmission lock up to a 1 wire lock up system that way all you have to do is run a single wire 12Volt ignition switched power fused at 5 amps. All that & new soft parts should run you $425 if the shop wants more they are over charging; assuming you pull transmission. They may suggest a new performance reverse input drum which costs about $75 more it's not a bad idea if you can afford it.
Well, thats my opinion on it just sharing so you don't have to go thru that learning curve I did back in the 90's.

 

you can reuse your stock plug with a little rewiring, no need to buy anything.. you just need to do a little reworking of the wiring on the valve body and tie a couple of the wires in the plug together to get lockup whenever it shifts into 4th gear... you can also get a vacuum switch from an 80's pickup to put inline with the wire from the brake light switch so it unlocks when engine vacuum drops when going up hills and things like that when you don't want to lug the engine but also don't want to downshift..

all that being said, i've put about 20,000 miles on my car without a lockup converter and haven't had an issue... i did wire it up, but i think the solenoid is bad because it just pops the fuse whenever i put one in it... maybe i'm giving up some gas mileage, maybe not, but i dislike dropping the pan more than i like trying to gain an extra mile per gallon on my summer cruiser so i never bothered to fix it..

 

Sorry, you answered my question in your post... Just saw it. Lockup is not essential, but what is absolutely critical if you want to keep your transmission, is that you get the right geometry brackets for the 700r4 TV cable that connects to your carb. Otherwise it will damage the tranny really quick. Holley makes one for their carbs, not sure about other carbs as Holley is the only brand I use, but I'm sure they all make one. Main thing is know this...yours will NOT work. In fact you probably will be needing two different brackets. A geometry bracket, and also a mounting bracket for the TV cable. Your stock brackets won't work with a new Carb.

 

DonW is right on about the 700R4 TV cable. My brother forgot to set his once only took 2 miles destroyed transmission. I saw a couple of your other posts that is a mild 350 u are installing. The 700R4 in stock form should hold up to that no problem. The one wire conversion probably not worth it at this point.
As far as the vacuum switch idea per novaderrik he really needs to run his thru a relay or at least a slow blow fuse. Solenoids have a high pull in current draw while having a low maintaining current draw. If I where wiring it for my own car I'd do the relay. Also I'd do a manual switch so the lock up doesn't activate in any other gear besides fourth. This is the cheapest way I can think of to maintain your lock up but you will have to remember to manually switch it on and off for when you are on and off the highway.

 

you don't need a manual switch the get lockup only in 4th: you just need a normally open switch in the 4th gear oil passage in the valve body that grounds the tc solenoid when it sees pressure.. most factory transmissions already have this switch in it so wiring is very simple to do.. with some valve bodies, you can also set it up to ground the solenoid in 3rd gear as well, i had the 700r4 that i swapped into my 74 Monte Carlo wired this way for a while... the vacuum switch i mentioned in my last post would not provide power to the solenoid when it's below a certain vacuum level, which would mean no lockup under WFO throttle conditions.

 

You just described what a one wire lock up conversion is. I reread your earlier post. I must have been tired or had a senior moment. You where describing a 1 wire lock up with a vacuum switch thrown in also. I don't think he will need the vacuum switch I think he has a 300hp motor. Even on step grades that should be able to pull the weight of the car without problem. I still do recommend a slow blow fuse or Mega Fuse 5A for that circuit due to solenoids natural tendency to have higher pull in current than maintaining current.
My 1 wire lock up conversion would pulse back and forth 2 to 4 times right at cruising at 36mph so I ended up putting a delay timer relay in the circuit.

 

I apologize for the incredibly late response, thank you for your help and I plan on using a edelbrock 600 carburator

 

Good choice of carb. Like the Holley 600, once set up and tuned correctly is pretty low maintenance. Don't forget the mounting bracket and geometry corrector for the 700r4 TV cable.