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Discussion Starter · #1 ·
my car used to have a 305 5.0 ltr in it. i just put a new 350 crate engine in it and i put a crane cam with a rough idle in it!! when the transmission hits first its a real hard hit! does that mean the trans is going out or should i put a new tork converter in it with a higher stall? i kept the original trans and converter from the 305 engine!!! if any body knows about transmissions id appreciate some advise! thanks and if you know where i can find the thransmission identication code on it cause i cant find the code any where on the trans i dont know what kind of trans it has?
 
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Discussion Starter · #2 ·
First I would check the kickdown cable for proper adjustment, you could be applying the passing gear too early if not adjusted properly.
 

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definitely need a higher stall speed in the convertor. a torque convertor is made to slip at idle to its max stall speed, then it will usualy only slip 10%. but in your case, having a 700r4 4l60 you have a lockup convertor also. this means when your car hits fourth gear it has a clutch inside the convertor that is applied via a solenoid that dumps pressurized fluid through a hole bored in the front input shaft of yout transmission pushing on a spring washer and engaging the clutch eliminating the 10% extra slippage in affect removing all stall out of your convertor. gm did this to improve highway milage. remember the higher the stall speed, the easier it is on the motor at idle. it is wise though to tailor your stall speed to the cam in your car. your factory convertor is a 1400 stall 28 spline with lockup convertor for the cars with the 7th vin (h) option. a better real world explanation would be your cam now makes your motor idle at 1100rpm. your stall is 1400rpm so you have three hundred rpm from a dead stop until your convertor is opperating at 90% which makes for a real rough takeoff. this is hard on a transmission given all the heat produced in a torque convertor. there is a company that sells lockup convertors with higher stalls called monster transmission. in all my searching they seem to have the most affordable products with the best warranty. also to adjust the throttle valve cable ( cable from your transmission to the carb) have someone sit in the drivers seat and with the car turned off, have them floor the gas pedal. then there is abutton on the cable at the carb, with the pedal floored press the button and let it go. you should hear a sleave drop back if it isnt adjusted properly. this cable tells the transmission throttle position and tells it when to downshift,(otherwise known as passing gear and when to deactivate the lockup solenoid. i hope this info helps you out.

also if you need to know what size stall to run tell me your cam specs and your final drive ratio on your rear end and i'll tell you what stall you need to run.... good luck..


is your idle this rough or how is it in comparison.. this is my car and it needs somewhere around a 3200rpm stall.

 
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