my import started life as a 1980 Corvette 305 I'm in UK but from what I understand this motor was for California only, with a 305 cu in (5.0 L) V8 engine rated at 180 hp (134 kW), fitted with new tubular stainless steel exhaust manifolds, and mated to a 3 speed automatic transmission, also mandatory in California. The carburetor and ignition timing were controlled by Chevrolet's new (at that time) Computer Command Control system. The smaller displacement engine was not available in any other state.
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At some point a 350 Mexican crate motor has been fitted (hp anyone?) along with an adjustable vacuum HEI distributor and a manually adjustable quadrajet. My question is; did these Californian cars have a lock-up transmission? How would I know and can I tell from the driving characteristics if it was fitted, is working or not?
Thanks

 

Get the driver side up on a jack or ramp and look near the side of the trans above the trans pan. If you see a 4 prong electrical connector plugged into the trans you have a 350 C transmission. No plug then a regular 350 trans.

 

80's do seem to come factory with lock up T350 C , my 80 L82 does , there's a good chance that the California Vette with 305 has a TCC controlled by the ECM like 81's are

 

OP trev
pull a valve cover and find the head's casting number; with an accurate CN, someone here can help narrow it down to which motor (& hp) is likely.

Block's casting number and the stamped numbers on front passenger side pad just forward of pass head will also be helpful.

Does its intake manifold have either 6 or 4 mounting bolts per Each Head?

 

My '79 import also had a Mexican replacement block. Those things have a tame cam and low compression, so if nothing else changed good chance you are at the same or lower HP at the rear wheels. Had mine dynoed at 150rwhp.

 

Chances are yours had TCC. Maybe a different trans now without or when previous owner removed electronic controlled parts it was disabled. Next time you have the trans pan off to replace the filter remove the solenoid from the valve body if still there. Over time they can clog with small amounts of particles from the clutches. Normally not an issue but these can cause the port to close locking up after the 1,2 shift. Just pull the solenoid when you have the opportunity.

 

When a trans goes into lock up, its almost like a minor percentage drop into a higher gear. If it's like any 4 speed with lock up, you can test it by cruising in 3rd, keep one foot on the gas and lightly touch the brake and watch the tach instantly climb a few hundred rpms.

 

As another poster said, you can look underneath for an electrical connection. The 305 came with a lockup TC. The issue is that even if yours has a lock up TC, did whoever swapped the engine bother to make it functional. I'm not sure on the computer control cars, but as the carb had a throttle position sensor it would not surprise me that the computer controlled the TC directly. On the non computer controlled cars, such as my 80 L82, lockup was controlled through various components, but among them was a vacuum switch which would close at 7 in. hg and open at 2.5. It would not surprise me if whoever swapped the engine decided not to hook up the lockup TC. Given the complexity of a 1980 vacuum system, many of the cars had the non-essentials disconnected as they failed or components were changed.

If you want to go on an archeological expedition, remove your spare tire cover, the spare tire, and the cover that's above it. Then reach up and feel around the top of your fuel tank for a sheet of paper. Do it gingerly as if there it will be brittle. If you find it, then you can pull your gas tank. It will be the build sheet. I could actually see mine partially hanging over the back of the tank. It was in various degrees of legibility. But it should have a code for what tranny went in. Obviously, it's not worth all that since there's easier ways to tell. But it's good history for the car if it's still there.