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1980 Corvette 305 - 'lock-up' gearbox?


CCCUK Member
my import started life as a 1980 Corvette 305 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.
At some point a 350 Mexicaan crate motor has been fitted (hp anyone?) along with an adjustable vacuum HEI distributor and a manually set 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?


CCCUK Member
If you’re referring to that fact that some torque converters have a lock up clutch then to test get up to 50ish press the accelerator lightly.

If the revs match the road speed it has a lock up clutch in the converter. If it acts like the clutch is slipping and the regs rise slightly before you gain speed then it doesn’t or at least it’s not working.

I be had the lock up clutch fail on an Alipina and you get a slight vibration and the slipping clutch effect. As what usually happens is the lining comes unbonded.

If the box isn’t telling to engage for some reason I don’t know how you’d tell.

If you can find a part number on the torque converter it would be a definite answer.