Difference in ride after 20” wheel install

[tley]

First I have to explain a little. I had a ‘70 stolen from me two years ago. I had two sets of tires/wheels stacked in the garage that I had intended to install on it (6 lug). Fast forward to current and the stolen truck has been replaced with a ‘71. The tires on the ‘71 are terrible (would go flat within minutes). I had a hard time seeing purchasing a used tire and after mout/balance being a little shy of a new tire and if I bought new tires I’m just putting tires on ugly wheels. I hope you get my drift. That led me to wheel adapters; I know it is not the best choice but, I could use what I had on hand.

So my question. After installing the ‘09 Silverado 20” take-offs the truck seems to wander all over the road and is very slow to respond to steering input compared to when it had the 15’s. Is this normal? Does it indicate that it's time for a front end help?
Thanks for any input