the small "L" sorta brackets that bolt to the side of the 6 are slightly different that the ones that bolt to the front of the V8, and may be can be modified to fit but have to be at the perfect angle
the 90 buck mounts are
the brackets that bolt to the block,
+ the rubber donuts and pins they go on [also different than
the 6cyl ones - longer] + the
necessary brackets that bolt to the front crossmember, which is the main thing you need, as the frames for 6's didn't get those brackets
the mounting setup for V8's in any TF truck was unique to the TF series, no part of it is used in later trucks, nothing is the same as used on the 6, and those big cupped washers that fit the donuts are not available anyplace else I've ever found - my time and frustration trying to come close to a factory setup any other way would be worth way more than 90 bucks!
Bill