1975 gmc indy official truck?

[1975gmcindy500guy]

Hi, I have a 1975 gmc that my great grandpa purchased at the race supposedly from one of the crew chiefs. it has a #27 on the mirror and factory bucket seats I dont know much about it it is all original and un touched so it is as it was in the race. its 2wd and has a 350 and auto. any info would be great I would like to know how many were in the race. I dont think they made replicas that year as there is almost no evidence of this truck existing.