The Olds 260 4-bl never existed. That engine had a 4-bl intake but the carb used was a version of the quadrajet with the secondaries blanked out. Olds did this so they did not have to cast a special 2-bl intake. It was easier to alter the quadrajet carb casting.
The first time I saw that combination run at Indy I told Jim Skelly and Dave Danish that it was wrong and did not come with a 4-bl. It took some persistent arguing on my part over a long period of time to eventually get the quadrajet removed from the 260 engine spec. For those who have never seen the blanked out 2-bl version of the quadrajet check this out...
http://www.ebay.com/itm/rochester-2m...50796919882%26