69 427/390Hp 4Spd with 308 posi performance Question

[Brad H.]

Sorry for the stupid questions recently about this. Anyone have experience with this combination? I've read the posts on the small block similar combination, but I am requesting your thoughts or experience. Is this combination a poor one?
thanks,
brad

[Bob H.]

Re: 69 427/390Hp 4Spd with 308 posi performance Question

Hi Brad:

If you want off the line performance, forget it.

I have owned both big block and small blocks with the 3:08. My 327-365 with 3:08 (yes they made them) was very difficult when starting off. Otherwise is was ok if you didn't want to wind it up quickly.

The big block with 3:08 was not troublesome at all from a dead stop. I guess because of the torque difference. Really not bad unless you want those powerful launches. I can tell you it was really appreciated when on the highway cruising at 75.

Bob

[Brad H.]

Re: 69 427/390Hp 4Spd with 308 posi performance Question

Bob,
Thanks very much for that! Might need to bump the gears up a bit maybe.
brad

[Bob H.]

Re: 69 427/390Hp 4Spd with 308 posi performance Question

Brad

I also had a 67 400hp with 3:55 gears. I think it was the perfect gear for that car.

Bob

[Michael B.]

Re: 69 427/390Hp 4Spd with 308 posi performance Question

I've got a '69 Coupe 427/400 with a close ratio 4 speed (M21) and a 3.08. I wouldn't have ordered it this way, but that's how it came. Anyway, it is not a problem at all off the line, tons of torque. It doesn't have rip your head off acceleration, but it does great on the highway/freeway for a car without an overdrive. Car feels like it would pull forever!

I've thought for years about putting a 3.55 in it....still might do it one day.

Mike

[Gary H.]

Re: 69 427/390Hp 4Spd with 308 posi performance Question

My 69 is 427/390, M20 and 3.08. Great set of driving gears. No issues driving around town and great on the highway. Plenty of torque, but acceleration is harder from a rolling start than a stop.

Gary

[Brad H.]

Re: 69 427/390Hp 4Spd with 308 posi performance Question

Thanks guys, I appreciate the experience!
Brad