ok so i got my original transmisson professionaly rebuilt at a shop less than three months ago... they put in the all the heavy duty things in the tranny like the beast sunshell, racing clutches, 5 pinon gears all that good stuff..... the transmisson also has a transgo shift kit and a vette servo and i got a new stall that stalls at 2400.... basically a 700r4 tranny capable of handling 650hp according to him.... so when i drive the car for the first time it shifts from first to second real nice.... but then i notice i wont shift into 3rd gear... the tranny does not slip or anything but its as if its stuck in second.... what would cause this.... i know its not the tranny internals because it was just rebuilt with heavy duty peices and this is my first time driving it, so it must be the valvebody..... we thought it was the cable being too tight or loose but that didnt work.... could it be the valvebody or the governer or checkballs.... also we put in the wrong vss switch, cause my speedo doesn't work... we have the right vss switch for my car now.... would this cause the problem.... i really need help..... my dad installed the shift kit and vette servo himself and told the people not to touch the valvebody.... so i was thinking since everything else was rebuilt but that it must be sumthin in the valvebody.... any info would be greatly appreciated......

I had mine rebuilt a few years back. It sat in the garage for 1.5 years. I had the same issue. Basically the same parts as yours. I took it back to the guy that rebuilt it and he said a "valve" had stuck. I'm not a trans guy, so that's about all I know. Cost me $35.00 for the trans fluid. Works great now.

sounds like you might have a vale stuck in the valve body. believe me, it doesn't take much to make a valve stick. check the governor while you are at it to make sure the valve inside it moves free.

MY dad Found three problems:
1st: there was a peice of broken seal lodged in the 2-3 valve... you can see the impression of the valve hittin the broken seal... so that fixes my shifting problem... thank god : )
2nd: the top part of the gasket was torn alittle bit so that may have caused some issues
3rd: wrong vss switch in the tranny replaced it with the correct one and now my speedo works....
everything shifts nice and hard just like it should be..... thank god for my dad because i would have to pay big bucks at a shop.....

Hey, how do you know which vss you need? The guy that rebuilt my trans replaced the gear because I went from a 2.7~ gear to a 3.70. Now my speedo doesn't work. He says it's not in the trans. thanks.