Here is my Square Truck 4x4 tire History.
Front fenders and Offset of rims are the Main issue of your Question.
I had a 76 Blazer with 40" Groundhog tires.
It also had a Non Factory 454.
It had a 6" lift with a 3" body lift and the front fenders required trimming.
I had a 78 LB Truck like yours.
I put the same 6" lift that was on the Blazer on it with no body lift.
I run 36" tires on it with no Fender modification.
A 4" lift kit with most aftermarket rims you can run 33" tires.
A home stack of springs or shackle kits always varies.
This is what my 84 LB Truck has.
The 35" I have on it required Fender (Hammering)
Also depends if you have a Drop arm on your steering box.
If the right to left turn ratio is not equal because the steering link is not somewhat level,
it will cause the front tire to get closer to the frame/spring depending on the offset of the rim.