I would think that 2:41 would be OK with a 350 or any other 1 to 1 tranny.But with an overdrive unit you would need to go somewhere around a 3:73 gear.I am running a 350 SB,and 700R4 OD tranny,with 3:90 gears.It gets decent performance and gets 20 MPG all day long.I am sure you will get other opinions here,but that is how I would go.

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