For what it is worth. I owned a T code back in 1975. It had a hot 289, 4 speed 9 inch rear. The front suspension was still 6 cylinder stuff. It had 4 bolt Cragar SS wheels on the front. This was a 66 coupe. I never had any handling issues at all. I drag raced this car for years. If the conversion looks like it was done properly, i see no problems. My 2 cents.