ok, here goes. on the mid to late eighties corvettes, what is the 4+3 trans? ive been seeing a lot of them for sale around here, i just dont understand what it is. any info...?

 

It's a 4 speed manual with a rocker switch activated OD on 2nd, 3rd and 4th gears. Wind it up in 2nd hit the switch it shifts like an auto to OD. Wind it up again, grab 3rd hit the switch back to direct, repeat. I never used the clutch on the OD shifts when I drove one for awhile. If you get the hang of it, it's kind of like having a close ratio 7 speed

 

I owned an 84 with that tranny. All it is a Borg-Warner T10 with an overdrive unit attached to the back. I wouldn't recommend shifting as described by 87RS. The OD unit was prone to failure through misuse. A better way to shift is to use the clutch, that way it takes the engine torque and not the OD. If you are looking for an eighties Vette, look at an 89 or a 90. The ZF 6spd was installed in 89. A much, much better unit.

 

I agree with x. The reason you are seeing the 4+3 units for sale isn't because the people who have them think they're so terrific; they are ditching them for something better. They sucked IMHO although they did allow for pretty decent gas mileage. All the people I knew that had them would leave the OD off around town or for serious playing (¿oxymoron?), but when they got into 4th and above 50 or 55, pop it on like the TC lockup in an auto trans.

To me, the worst thing about driving it was the shifter. It didn't have a high-performance feel at all.

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"So many Mustangs, so little time..."

 

Well thanks guys. That clears it up. Dosent sound like something i'd like to drive.