Good to see an oldtimer resurface, zukimon!
I run with 30" tires a lot on the street/interstate with no problems. I can't speak about how 32 inch tires will do - especially without knowing the gearing. With those tires, you may not have a fifth gear anymore without good gearing.
Look at the axle perches. If the new ones are mounted exactly opposite or parallel to the old ones, you should not have any problems with driveline vibrations or excessive u-joint wear. If not, some perch repositioning is in order.
Does it have a drop pittman or some sort of OTT steering system? If not, you will have serious bumpsteer - the steering wheel violently twitches when you hit a bump. A Z-type draglink will NOT fix bumpsteer!
The best way to find out the condition is to drive the truck on the highway at speed and see how it feels.
Naturally, the more problems that you find, the lower the offer should be.
BE SURE TO SHIFT IT INTO AND OUT OF 4WD A FEW TIMES! A bad t-case shifter sheet can cause a deep cut in the price offer to your benefit! (

Yes, I am evil at times...)
I hope that this helps