I have a 1966 Mustang with a 200 6 cylinder engine which I took out and am replacing with a high performance 289. After several attempts to install, the mechanic says the engine can't be hooked up to the C4 and that I need to change the transmission.He claims there are two types of C4 transmission and the new engine needs the different transmission, that mine cannot be attached. I don't know much about this and I'm beginning to doubt that the mechanic knows what he is doing. Is he correct in...

C4 automatic transmission concern