View Full Version : Good Gear Ratio for 85 Bird w 351W HO and AOD Tranny

03-03-2005, 10:01 PM
How low of gears should i get for my 1985 T-Bird, which has a 351W HO and a AOD tranny. It has whatever the stock gears are in it now. Would 4.10 be too low?I still wanna be able to highway cruise too though. What would u guys suggest for this setup(AOD, 351W)?

Also, should I get a spool for it, of just a posi for it?

My goal is to beat a 1994 Mustang 5.0HO, Auto off of the line.

Thanks, Robert.

03-03-2005, 10:54 PM
you cant go wrong with 355s or 373s. 410s are a little on the steep side to do alot of highway cruising. id stay away from the spool as they erent realy street friendly and you said its gonna be highway/street driven.

03-04-2005, 06:06 AM
Some questions for you:
1.) What make/year is the 351 coming from?
2.) Have any mods been performed on it?
By answering these question you can give an idea of where your power is in the rpm range, but 3.55's is always a safe bet.

As far as a Spool, I'd stay away from one unless you do a LOT of 1/4 mile passes.
If you want a little more grip than a Posi(traction-lok)
http://store.summitracing.com/default.asp?target=/egnsearch.asp&N=400018 for 8.8 rears
http://store.summitracing.com/default.asp?target=/egnsearch.asp&N=400018 for 7.5 rears ( I have this one and am quite pleased with it.)