[1969 GMC]

I can add a little more here...trucks with the blazer/burb tank will have a slightly better weight ratio front to rear. But, I never really have liked the idea of the gas tank being under the vehicle because it could easily get punctured offroading (been there, done that, will never go mudding in a cornfield again!). Also, around Ohio we have this thing called "rust". I know you Kalifornians have never heard of it, but it does bad things to classic vehicles. I know its not a big issue, but I would be leery of a gas tank rusting and leaking. At the garage where I work, one of the buses accidentally did not receive undercoating and the OE gas tank had to be replaced after 2 years due to rust through.

Oh, and as to your #3....they are classic gm truck slang. its ok, hang around here long enough and you will be fluent in this language. OE buckets are Original Equipment bucket seats, which means factory optioned buckets, which are sought-after by many people. 402BB means 402 big block, which was offered from 1970-1972 as an option in all 2wd trucks. Welcome to the board!