So when I bought my car the paperwork at DMV showed there were two owners befor me.( Salvage ) The car has fairly quick/hard 1-2, and 2-3 shifts espicialy now that I put in a Corvette servo. With the new gears I can bark the tires at both shifts at WOT.(thats with 295/50r15s) And with all my tools in the back. About 60 lbs. worth. I can also hold the 1-2-3 gears as long as I want manually. Is any of that a indication of a previously installed shift kit?

 

i have a hard shift into second but not third. im curious to see the outcome of this thread. at wot shift into second gets my car completely sideways!

 

i aslo have a hard shift into 2nd but sometimes i cant even tell that its shifted into 3rd, first is the same way

 

my car also will do this with the 700r4 with the Corvette servo i have to drive in over drive or its begging for more gears. its just the 700r4

just some info

3.06:1 First gear and 1.63:1 Second gear found in the 700 are both lower than their counterparts in the TH350 and TH400, providing increased acceleration. The combination of lower First and Second gears and an overdrive cog give the 700-R4 the potential to be a good real-world performance transmission, promising the best of both worlds: acceleration and mileage. The overdrive cog also gives hot rodders the ability to run stiffer rearend gears without unduly affecting fuel mileage at cruising

 

I had the same issue and solved it by adjusting the detent at the throttle. Every time you remove throttle the detent needs to be reajusted. I had play in the cable wire so there was a lag in going to second which slammed 2nd even a slow acceleration. Big difference in 700R4 operation with proper adjustment.

 

I added a shift kit in my old 91 bird I had and got the good hard tire squealing second gear shifts, plus quite often the third gear chirp under heavy acceleration, but normal driving just a good chrip and pull for second gear, Id say you probably have a shift kit, thats what I think. Also if this helps when the car is first started and idleing around a grand, when Id put it in gear (od) it would lundge forward and chirp the tires right through the brakes no matter how hard I had them pressed, and they were all new and perfectly working brakes. I had a few other extras under the hood, but nothing much for a 305.