Th 350 Issues

[engineman85]

i have an 85 c-10 with a very strong 383 i destroyed my 350c that was in the truck and opted for a built th 350 non lock up trans about a year and a half ago. now my trans is beginning to slip at low throttle and it is getting an occasional chattering from around the converter area. the last time i heard the noise i had split my flex plate in six pieces and i thought i had done it again but the noise is not constant and it happens at random. i have a 2300 stall converter wich should be fine maybe even a little low for my cam shaft and i have a set of eaton 3.73's in the rear end. my question is could my converter be going out or is my entire trans in need of replacement? the slipping is very rare but it does tend to hold out in gear a little longer than it used to....any help would be greatly appreciated.