Yeah, the 351 had a longer stroke, my memory on this starts with the 302, lol. I saw SBC 350's with oval'd bores that needed a ream but the 302's were always immaculate. I assume it's due to them being very over-square, 4" bore, 3" stroke.
The Ford 302 also has a relatively short Connecting Rod & Deck Height, In fact the Rod Ratio or Rod to Stroke ratio is pretty close between the Ford 302 & the GM 350.
*302..........5.090" rod length divided by 3.00" stroke equals 1.68 Rod Ratio
*350..........5.700" rod length divided by 3.48" stroke equals 1.64 Rod Ratio
*351W......5.956" rod length divided by 3.50" stroke equals 1.70 Rod Ratio
This ratio expresses a geometric relationship between the rods, crankshaft and pistons. The lower the rod ratio, the greater the side forces exerted by the pistons against the cylinder walls.
While the 351W has a longer stroke.....Because it's Taller Deck, Making room for a Longer Rod, Has a little better Rod Ratio in terms of cylinder wall loading.
I've tore down some high mileage 350 SBC's with really good round bores & very little measurable Taper, They were 90's blocks with fuel injection.....Mostly Gen 2 LT1. Better casting techniques, Better Iron, Fuel Injection, And better oil all contribute lower cylinder wall wear.
The Iron LSx 6.0L is one of the best wearing blocks/bores I've ever seen, Even with close to half a million miles.
GM 7.4L/454 are the worst I've ever seen, In fact I can place my Bore Gauge in a cylinder where it won't fall out.....Using both hands & squeeze the the top of the deck over my Gauge & the Gauge will fall out! I can distort the bore by hand!