My vote, 3.42 gears as the magic gear ratio. My 1971 GS350 Convertible has them, stock th350 trans and tire size. True statement about over 70 MPH. My 1970 Riviera has them (swapped out from 3.08 originals) added 4L80e OD trans because I did not like running 3500RPM @ 75MPH. My 1987 GN has them (stock) original. Built 200 4R trans. My 2002 Tahoe has them stock. I am thinking about OD for the convertible. But I am living with it since I don't do much highway driving.
I really liked my 2.56 gears with 455...plenty of torque and power and great cruising...it's not a SBC. With relatively mild motor it still ran 12s. I would go 2.56 (cruise and fun) or go with 3.42 up and let it eat and race........in the middle ...2.73 to 3.31...is dead zone IMO
Where to find those 3.31 gear ? Any links to website ? I'm about to make my mind between 3.23 to 3.42 ... never heard of this 3,31 before , sounds good to me
I'm planning going from 3.08 to 3.42 on my '71 350 GS convertible too w/the TH 350. Would love to eventually go to a 200-4R & 4.56 (final drive ~ 3.08).
With the stock Buick only 8.2 10 bolt rear of a 68 Skylark, you don't have any choices at all. There are no new gear sets made for that rear at present. Looking back at your posts, I see you have the 12 bolt Chevy rear. That changes everything. https://www.moserengineering.com/12-bolt-331-p-s-gear-us-gear.item https://www.strangeengineering.net/product/gm-12-blt-3-31-standard-gear-set.html/ https://www.ebay.com/itm/222343310691 https://www.summitracing.com/search...n-ratio/3-31-1/ring-gear-diameter-in/8-875-in https://www.motivegear.com/auto-par..._viaSearch=path:part%3Aring-and-pinion;page:6
