I apologize if this is the wrong forum. But I have an '86 Firebird with a 305 that's carburated, the computer just controls the shift point for my 700R4, I believe, and some pollution stuff, maybe even the carburater some. (I'm not real sure WHAT it does...) But I just pulled my motor and tranny and am putting in an Oldsmobile 455 and the 700R4 after it gets rebuilt. But my question is HOW can I pull the computer stuff, the 455 won't need it, so I want to junk it.(There are lots of wires left and I don't know which ones to keep and which to pull out.) I looked for tech articles on it and couldn't find any. Any help would be much appreciated. Thanks!

 

The only thing the computer does on a 700R4 is lock the TCC (Torque Converter). You can either wire up a "switch" or go to a non-locking TCC.

You do realize a 700R4 doesn't bolt straight up to a Olds engine don't you? And a torque monster like a 455 is going to kill a stock 700R4. You may wish to look at other alternatives on your tranny like a 200 (if you want the overdrive). It has better "gear ratio" in my option than a 700R4 and some consider it stronger (though it too will probably need to be "beefed up").

 

I realize that I'm going to buy an adapter kit for the 455 to bolt up to my 700R4, I can get one for $56 through summit. As far as the 700R4 compared to the 200R4 I was planning on beefing up the tranny to handle the power, so I think that'll be fine. I'm going to get hardened internals and a shift kit. Should I just pull the computer and then whatever wires come with it? I'll talk to my transmission guy about the non lockup TCC. THANKS!

 

when you get it rebuilt the tranny shop can modify it so that when it goes into 4th it automatically locks up there is just a little difference in a fluid path somewhere, I used to sell these from a tranny rebuilder when I worked at a parts store in texas, the company made these especially for older cars that were getting converted. made it a lot easier than trying to wire in an external vacuum operated lock up.

 

I went thru 5, 700R4s in my 355 SBC's 3rd Gen. This was at 325 HP, and yes I beat on it, but that's the way I am. The only way I could get it to live was with a NON Lock-up converter. In a high HP application you will chew up the TCC linings in a 700R4.

I have a 200R4 in a much higher HP GN now, and not a whimper. Thou it's not stock.

The 3.06 1st gear in the 700 is nice for lighting the tires, but that loses races. The 200R with 3.42s is MUCH nicer then the 700 with 3.23s, IMNSHO....