Slant 6 to 340 Engine Swap in 69' Dart

I can’t use the K-member that’s in the car now with the 340?
Even with the motor mount adapters?
If not, why?
As stated, trans is out, the T-bars are most likely .850" dia., 340-360 cars would've been .870", stk Slanty is .830". Adapters are adapters, they'll bolt the engine in, but if You look there are V-8 K's for sale here & elsewhere. Throttle pressure linkage complete, throttle cable, trans, rad, hoses, driveshaft(or have Yours shortened), add leaves to rear springs or get correct new ones,off the top of My head.