guitarman376

I just hooked up a tach in my car for the first time, and I was shocked to realize my car has either 3.0 or 2.79 rear gears (I think 2.79). I haven't had a chance to check out the ID tag if there is one but its definitely one of those two ratios. I know my tire height and used a calculator to figure out what rear gears my car has. Currently the car has an FMX.

I am going to eventually swap to a wide ratio toploader, but with what I know now I am worried this won't be the best combination. Basically I wanted to hear from anyone that has a 4 speed and gears like this to see how they feel about their setup. Anyone?

Otherwise I will have to save even more to rebuild the rear end at the same time I do the toploader swap. For something that sees the freeway a decent amount I will eventually go to 3.25. My motor is stock, but will eventually have a carb I/H/E but that's it (maybe an extremely mild cam one day). I mention this so that you know the powerband is low-end just like the 351w's came from the factory.

Starfury

I started off with a 3sp and 2.79's. Cruised great on the freeway, but was always a dog off the line.

I changed to 3.25's after the 331 build and noticed a huge difference in acceleration. Cruise rpms went up to ~3200 @70mph, which is OK for the motor build.

Swapped in a close ratio toploader and I absolutely love it. First is a dog, but once it's rolling it's a blast.

I think you can get away with the gears temporarily, but it should be OK with 3.25's if you really want to drive it on the freeway.

guitarman376

I am thinking that as long as I continue running a cam that makes power off idle to ~5000rpm it shouldn't be too bad to start from a stop. The thing is, I really like the gearing I have once you are moving...

Nosara

I ran a 4 speed toploader with a2.79 eight inch open for years. It did just fine. With that gear box you can make anything snappy. Lot of fun and I even autocrossed it way back when. Second gear was perfect for AC runs.

guitarman376

Good to hear fellas. I want to put off changing anything in the rear end for as long as possible. I have been asking any and all questions regarding toploaders etc for a while now, even though I am not yet at the stage to start the project...I'm a planner for sure.

Starfury

Better than the other way around It's never fun when you get halfway done with a project to find out you need to redo parts of it, or completely replace a related system because it's not compatible.

drewsky

had a 3.0 with my 4 speed prior to the 3.25 i put in it now. the 3.25 is my favorite gear for classic mustangs. but the 3.0 was not terrible at all