Motorhome 440's... factory seconds?

I think you have a point 70 Duster, but even the HP motors will have undersized journals, overbores and anything that will get the motor done and into a vehicle. There is absolutely nothing wrong with undersized machining, bearings or anything else that may have had to be done to a motor to get it finished. As quick as assemblies had to be finished at put together, it's no wonder why stuff was put together in such a manner.

And don't think for a minute that the best parts were put on the line and the seconds ended up on dealer parts shelves. QC was bad all across the board back then, and ill-fitting parts were used all the time, on the line and in the repair dealership. Take a look at how hastily a Superbird is put together. Some original paint cars have primer showing right through the very thin overcoat, paint runs everywhere, and such poor fit and finish it would be scrapped out today!! I've seen rear window plugs with as little as 4-5 tackwelds holding them in place. You'd thing a high profile car such as this would get the full treatment, not the other way around, but it was get it down the line and sold and we'll fix it later, IF we HAVE to!!! Geof