i am looking to put a th350 in my 99 LS1 car an going with a 4000 to 4500 stall but see that they have a lock up and non lock up convertors ??? whats is the differance

 

One has a lockup clutch and one does not..

 

to give you a better explanation a lockup converter has a clutch in it which could be compared to a manual clutch it locks the engine and the input shaft 1.1 a non lockup converter will never turn 1.1 even at coupling speed there is a difference in speed of the 2 about .93.1....the converter clutch is used for gas mileage and emmissions it can also be used to lower the temp of a tranny..basically it feels like another gear when it comes on so in a 3 speed tranny after 3rd hits you would feel what feels like another shift but it would only be the converter locking in

 

in a 1/4 mile pass is the lock up or non lock up better or would it not play a factor.im not interested in gas miliage.i just want my 1/4 times low

 

That would be a non-factor. Some people like to lock it at WOT as it can help improve MPH if you have a really loose converter. You need a really good clutch though.

Normally its used for efficiency at part throttle.

 

thanks blackhawk