hi just my .02 cents here. i have a 605 box I installed in my 59 chevy with an adapter plate and i have not had a single problem with it. I know from reading on here that grandpaws had a miserable experience with his 605 but that was a modified box so i believe there lie's the problem. GM HAS PROBABLY USED MILLIONS OF THESE BOXES OVER THE YEARS so they aren't that bad if left un modified
grandpaws sorry to hear you had a bad box.i had one on my 55' chevy that i personally modified and never had one problem great thing was it cost me 16 bucks!, the price of the box at pull a part. i have a 60' sedan delivery that has one going on it also.