In 78 the lower model broncos had round lights, the XLT's & Lariets had the same square ones as the 79's. In 80 the frames were lightend up too much , by having holes in it all over the place, the 80's ford light truck Knocked Ford out of first place For sales, a title they had for many yr's with the " ranger "style of trucks.(67-79), the 70's trucks never came with power acc.They are alot heavier, but the frames & other comp. are the strongest 1/2 ton driveline made, c6-205-rear 9"-frt. dana 44. If you don't have a 79 bronco , then you want all the driveline to put in yours.Oh yea the engines are lame , but thats what 460's are for !