Have a 92 firebird with a 305 tbi and plan on swapping to a 350 carb. Have heard that there are problems with tranny, gauges, and fuel pump. Want to know if there are any other problems and how to deal with those that I know of. I know that I could remove stock fuel pump and replace with in-line or a few other options but I am not sure about tranny and gauges.

Tranny - you need to provide some means to lock up the torque converter, since the ECM will be brain dead.

Gages - no problem if you retain the original wiring to the sending units. If you have electronic speedometer, that could be an issue, but I don't know exactly what you have to do to rectify that.

Fuel - You can run a regulator that utilizes a return port and retain the electric in-tank pump. Whether it is capable of feeding a healthy 350 is open to debate. The alternatives involve removing the in-tank pump (you might be able to "get by" with leaving it in there, but is it really worth the risk?).

Im about to do the same thing in a few months(going from lo3 to a 350 HO deluxe,personally).Im doing "homework" in preparation.

So five7kid,could you elaborate on the converter part a little more please?My plan was to swap the stock tranny for a 350 turbo and stock converter for the one in the S-10.I was going to replace the fuel regulator and pump for higher flowing as well.Please correct me if my thinking is off.

Anything else I need on the "replace" list?

Thanks bro.

you must run a hot wire from the valve linkage that controls when the converter locks up to somewhere inside the vehicle where you can switch it on when you want it to lock up. Typically that is after one reaches 35 mph, and use on the highway. You can ignore the whole thing if you want, the only thing is that your motor will run at 200-300 rpm higher than if you lock it up.

I realize that I am not five7kid but I have been told by a reliable source what must be done for that particular problem.

From the discussions on the Tranny forum, it's not a good idea to run a clutch-equiped TC in a TH700 without the clutch operating. Excessive heat production will do damage to 3-4 clutches, etc.

There have also been numerous discussions about alternatives to provide the lock-up function. The electrical power already goes to the tranny (via a switch contained in the brake light switch), what the ECM does is ground the circuit to activate the TCC solenoid.

So I gotta rewire it.Gotcha.Wow thjs swaps looking better and better.It'll be worth it in the end though....

But heres a dumb question.


Whats the difference between lock-up and stall? :lala:

"Lock-up" means the torque converter is equipped with a clutch to eliminate all speed loss between the engine and transmission in cruise conditions. In the early 80's, the factories started using such transmissions to improve fuel economy ratings.

"Stall" is the maximum RPMs a given engine will reach with a given torque converter without the vehicle moving (being held by the brakes or a tranny brake). This isn't a "hard" number - the same converter will "stall" at a different RPM behind engines with different torque characteristics. For instance, when I was looking for a converter for the Camaro, the outfit I ended up getting this one from guessed that it would stall around 2000 RPMs, based on what I told them about the engine. In reality, it stalls at 2300. He said the same design converter stalls at 4500 behind one customer's Vette with twin turbo 350. Another example, the "Boss Hog" converter in the '57 is called a 2800-3200 stall - it stalls at 3500 for me. A racing buddy has the same converter behind a 454 in his '65 Chevelle, it stalls at 3200 for him.