[special-K]

Is it a C/20 3/4t or is it a C/30 1t?

1- You can use later seats but some holes don't line up. If just needing the bottom, you'll want one from a 67-72. If you had the correct seat brackets you could put them under a later seat.

2- 69-72 hoods exchange. 69/70 have the bowtie, 71/72 are plain, and 69-72 GMC have GMC letters. The holes can be dealt with, but those are the only difference.

3- I'm pretty sure 3/4t and 1t boosters are the same. The wheel cylinders will be through '70. Your best bet is to look them up online by year and see if part numbers match.

4- Those covers just have to come from a 4spd truck

5- Not sure on the sending unit, but the tanks are all the same except the fill spout on later models. I believe those would all be the same.

6- 69/70 share the same grille surround with '69 insert having rectangles in dark grey and '70 having fine raised bars in silver with black background. A very minor difference on old grilles.