Regular vs Big 10

[seanconnery]

Is it safe to say that if you have a 250 inline 6, then you probably don't have the "Big 10", or "heavy half" options?

[dswancutt]

Couple of minor corrections I would like to point out. ALL 73-80 1/2 chevys have the big rotors. The smaller rotors didn't start until 81. I have looked in the chevy parts manual and have confirmed this. What the Big 10/Heavy Half gets you is the double diaphragm booster, 2/ 3/4" wide rear brakes.
My 78 Big 10 does not have the 2 piece drive shaft or double hump crossmember, and it is the last year for the no smog trucks.
And you could get the Big 10/Heavy Half with any engine package.
And as far as helping with pulling a trailer, it will. I also have a 79 that is a 6 cylinder and has the heavy rear spring option and a bumper pull stock trailer barely even sags it.
Hope this helps.