Gearing shenanigains

[brownsvo]

Alright what am i doing wrong?
I have a picture somewhere of my RPM/Speedo at 3000rpms/70mph.

Now plug that into a calulator (http://richmondgear.com/101032.html) with a 26in tire (i actually think stock is 25 which i think i have) and i get my rear end is a 3.3~


I know we've all heard it before i can never be too sure since i am not the original owner and it could of been swapped. I only ask because i was trying to figure out what would be better to get my rpms down to 2500 @ 70mph (2500@70mph) by switching to v8 transmission or a gear swap.
As far as i know my car is a normal 85 (1FABP28T8FF154031) oil-cooled,e6 manifold.

so what is it, is it my math or the parts not adding up?

[Raven855]

With your vin number, it appears you do have an 85. The stock tire on the SVO for all years was a 225/50R16. The nominal tire diameter is going to be 24.858 inches. You could use the 84 differential which has a 3.45 gear to get your revs down. Lots of things that you could do including swapping transmissions. Its all a matter of what sacrifice are you wanting to make. Be aware that the V8 transmission is not a direct swap.

[Chalky]

I'm running an 85 tranny and my 8.8 has 3.55 gears. I'm seeing 2500rpm at 70mph and get great mileage. I'd just have a set of 3.45 gears put in if you have the stock 7.5" rear.

[brsvo]

Get an 89 4 cylinder trans with .79 OD. My 84 has this with the 345 gears and at 70 its about 2600.

[brownsvo]

the svo came with a .78 5th gear i thought so a non-wc 4banger trans wouldnt be worth the trouble
(sourced from : http://www.allfordmustangs.com/Detailed/349.shtml )
i dont see much of a viable option for a lower 5th other then a v8 trans.

I drive less than 2 miles to work so i think it might be a waste to do all the work for highway speeds lol..
I like the idea of road tripping the svo (and not breaking down midway) 300 miles and getting 26mpg @ 70mph like i did in my mach1.

[Meotchh]

i dont see much of a viable option for a lower 5th other then a v8 trans.

If you use the V8 you will need a bushing on the V8 input shaft. The bronze bushing can be purchased through Grainger or McMaster Carr. I would have to look up the correct part number. I purchsed one through a Merkur site many moons ago before I found it on McMaster Carr.