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AzDon · 03-04-2014, 08:34 PM

Too many RPMs for the highway with your current setup..... I'd do BOTH the 700r4 conversion AND a more highway friendly diff ratio....
My 68 Burb runs a 700r4 and 3;07 gears..... At 75, it purrs along at 1600 RPM and gets over 14mpg..... around 10-12mpg around town.....Pretty good for a 350 with a Holley Double-pumper!

03-04-2014, 08:34 PM	#5
AzDon Registered User Join Date: Oct 2008 Location: Lake Havasu,AZ Posts: 202	Re: stay TH350 or convert to 700r4 Too many RPMs for the highway with your current setup..... I'd do BOTH the 700r4 conversion AND a more highway friendly diff ratio.... My 68 Burb runs a 700r4 and 3;07 gears..... At 75, it purrs along at 1600 RPM and gets over 14mpg..... around 10-12mpg around town.....Pretty good for a 350 with a Holley Double-pumper!