I'm going crazy, need help with trans/gear ratio

[Anthony14]

I'm going crazy and need help. SBC350 and TH350 transmission. 3.42 rear end, 29.6" tires, TCI 328800 rebuild kit/shift kit, TCI Breakway 240900 torque converter. 60MPH @ 3500RPM!!?? When I installed the torque converter to get it to idle in gear (cam dur. heads etc...) it fixed that problem then had these high rpms at cruise. I tore the transmission down cause TCI and Summit said that it sounds like it was slipping. I found some burnt clutches and steelies. Installed the TCI rebuild kit and now I have the extact same problem! I should only be at 2330rpm according to Summit's gear ratio calculator. I'm outta ideas...