[gtorich]

Originally Posted by Andre

The beauty of the Pontiac V8 is that it has more than enough low end torque so that gears like 2.56:1 will still burn the tires. Case in point being my old 1964 conv clone with stock never taken apart 389 and 2 speed auto with 2.56 rear and 14" tires. It would smoke these tires with no effort, yet ran cool as a cucumber (just at 180) at 2000 rpm at 60mph. I think the new owner loves it more than I did.

Hmmmmmmmmm not doubting this in any way, have a 455 kre heads ported by SD with a 3.42 rear, 4 speed, yes it will smoke the tires, but not without some effort. just replying to many posts about smoking the tires while just touching the gas..............doesnt seem like mine is doing this.

Rich

[north]

3.55's were often the go to gear from the factory with a manual trans with 3.23's for AC applications. 3.08 was typically the lowest numerical axle offered with manual trans (before the fuel economy desperation era). 3.08 is definitely not an unreasonable gear for a 400 but it is near the limit.

[geeteeohguy]

Originally Posted by north

3.55's were often the go to gear from the factory with a manual trans with 3.23's for AC applications. 3.08 was typically the lowest numerical axle offered with manual trans (before the fuel economy desperation era). 3.08 is definitely not an unreasonable gear for a 400 but it is near the limit.

Back in the day, '70's-'80's, several of my first-gen GTO's had 3.55 gears, which were just fine. The national speed limit was 55 mph, heavily enforced, so we could cruise on long trips at 58-60 mph and not get in trouble. The car was happy at that speed. Fast forward to now, with 70-80 mph cruise speeds, and 3.55 gears suck. You are wound out and running hot at 70 mph, and guzzling fuel. 3.08-3.23 are PERFECT gears for a wide rato manual 4 speed, non overdrive Pontiac with 326 or more cubic inches.

[1967Tempest]

I ran a 400 with a Saginaw 4 speed with a 3.31 first gear with a 2.56 one legger for years. Super fun to drive on the highway as it would get great MPG and you could keep up with traffic at 80+. Plus high speed! 80 MPH was right around 1750-1800 with a tall tire. I did end up going to a 3.23 rear and it was def quicker, but the MPG's def went down.

Now the car is very low to the ground with a 468c.i. engine and a TKO500 and a Ford9" with 3.50 rear gears. MPG is not great, but I'm gonna put in a Magnum 6 speed here this winter. The 5 speed is going into my LS swap Volvo.

[torchred]

Originally Posted by geeteeohguy

Back in the day, '70's-'80's, several of my first-gen GTO's had 3.55 gears, which were just fine. The national speed limit was 55 mph, heavily enforced, so we could cruise on long trips at 58-60 mph and not get in trouble. The car was happy at that speed. Fast forward to now, with 70-80 mph cruise speeds, and 3.55 gears suck. You are wound out and running hot at 70 mph, and guzzling fuel. 3.08-3.23 are PERFECT gears for a wide rato manual 4 speed, non overdrive Pontiac with 326 or more cubic inches.

I had 2.93 s w/ wide ratio muncie great on the highway but hard on the clutch
3.23 was worth the switch.

[lugnutx2]

No problem with 3:08's / M20 combo, that's how my 66 TP came when new.

[geeteeohguy]

Originally Posted by lugnutx2

No problem with 3:08's / M20 combo, that's how my 66 TP came when new.

I agree. I would run a 3.08 with an M-20 in a heartbeat with anything with a 326 or bigger engine. Not a problem at ALL.

[gtospieg]

I ran an M20 with a 2.56 Safe T Track back in the '80's in my 67 Tempest 326 4bbl and dual exhaust...got 20mpg on the highway cruising 65...not bad I thought.

[gtobird]

My 68 Bird convert was built with 3.08s from the factory with an M20. No problem at all driving it when I was a much younger redneck. Of course, I was married at the time and my burnout days were mostly behind me......... LOL