Well, Sir, I have carried gas to this particular 70 in question (pulling a 3x14" with no coverboards, jointers or moldboard extentions..
At the same time we had 2 WD-45 AC's pulling 4x14" with coverboards and moldboard extentions..
In that 1/2 mile long field, I would PASS the 70 every 2 rounds with the WD-45. The WD-45's averaged 1 1/3 Gal per Acre plowed.. The 70 was burning over 2 Gal of gas per acre.. The 70 was fairly "Fresh", with a new valve job that Spring.. I can assure you that my 630 uses far less gas than a 70 and will do the very same job.. From my personal experience, I would not own one of those 70 Gas Hogs..