What can i swap directly, i have a 700R4 with a 350 Carb'd infront of it and it wont go past 2nd and im at about 4 grand and its a knockin' form the start up. and its not my engine because we just swapped it out because of the same problem misdiagnosed, but still needed the old LG4 was knockin too and was ran hard for 210,000mi and had cheap oil. so i was wondering if i could swap a TH350, and how much change for a TH400?

Thanks Guys

 

The TH350 is an easier swap then the 400. I'm doing the 400 swap now. either one requires a torque arm adapter from B&M or Hurst but the TH400 requires a modifed crossmember. The 350 needs a TH200C driveshaft but the 400 needs a new driveshaft due to the larger slip yoke. I chose the 400 cuz i'm tired of blowing up 700R4s and wanted a stronger foundation then the th350 could give.