Even with the AOD I suggest going 373's...gives you more room to play with...here are some things to consider with the AOD or 5spd (if you convert later)...
Go with 373's or 3:55’s on a daily driver (that is my suggestion)...I'll put some info for your gear selection decision. If your worried about "hurting" anything the 373's will technically be better for you over the 410's...
373’s will be more daily driver friendly and if you get boost/nitrous later you won't run out of gear at the track and you will have less traction problems. Some that have actually had both gears were slower at the track with 410's over 373's and some also claimed no seat of the pants difference.
I run 2400 rpm at 70mph (I have 373's)…the 410’s will run higher closer to the 2600-2700rpm range with the 245/50/16’s I have on my car.
Here is how I look at when picking gears for a daily driver...To me the gearing of 410's or steeper on a daily driver is not worth it to me...you get worse gas mileage/more engine wear/and use your shifting components more (clutch/trans/etc)...around town...and I also look at it like this...when your cruising on the highway at 80mph (interstate) your cruising at roughly 3000rpm with 410's...that is HALF your 302's revving capabilities and that is in the overdrived 5th gear at CRUISE...not at WOT...I personally don't like the idea of having half the engines revving capabilities at just cruise. Also...what if an emergency comes up and you got to "get it"...you have to be there for someone or are running to the hospital...and running higher than 80mph...maybe running 4500rpm steadily (faster than 80mph of course)...during that emergency I don't think that would be a good time for your engine to let go on you...what do you think?
Then you have to factor in 410's or steeper cause my engine braking at higher rpms on the highway...go pull out somewhere and hold your car to 2500rpm or so (worse with gears) and feel the engine try to slow you down when you let off the gas...same similar occurance happens on the highway/interstate plus the wind resistance.
I know when I had the slipping clutch problem I could smell the clutch burn at a higher rpm cruise which in my case was comparing 2000rpm to 2500rpm. At the lower rpm I didn’t smell it but the higher rpm I could smell it. Just some things to think about when you think you want every little tenth out of your car (4:10’s)…I prefer a better overall performance personally…
Go 373's...I would rather want more (373's to 410's) than get to much (410's) and want less (373's)...get what I'm saying?
There will also be less drivetrain shock under traction with 373's over 410's...
The problem with 410's in an AOD is you only have 3 gears to work with at the track (effective gears anyways) and the gears will get you out of those gears quicker and you could lose your gearing powerband at the track.
Also if they were to convert to a t5 (pretty popular actually) then they are "stuck" with the higher revving 410's...I hate the "winding out" sound on the highway with a gear like that...
On the listing of "pros/cons" of a mod like gears. I have stressed that in a couple choice threads, for example on shorty vs. longtube headers. Longtubes will get a better midranging power over the shortys (so the pro is more power) but some forget to mention the cons of it which are buying a matching mid-pipe (more money and aren't able to use the stock mid-pipe) along with ground clearance issues (especially on a lower car) and also the difficulty of install is "stepped up" quite a bit when trying to get longtubes in. It also can cause heat-soak issues and steering column clearance/rubbing issues. The potential purchaser has to ask themself is the extra midrange worth it? Then you get your answer...
So I ask...are the 410's (a tenth or two quicker at track to a matched combo over 373's) worth it? (more engine/drivetrain wear/worse gas mileage/and a couple other "cons" listed above in my post)...again the potential driver/purchaser has got to ask themselves what they want
willys1 (member on this site) actually was slower at the track in his bolt-on car with 410's than he was with 373's...and his is an AOD...
To often people go "drive" a friend's car with gears and go have fun in the car and don't drive it normally or thing of longterm effects with normal driving. They often just use their SOTP meter to determine what gear they want but when a final gear ratio effects all different parts of you and your car...I think it is best to not try a gear ratio "drag strip style" but "daily driver style"...
I have rode and drove in every car except one with 4:56’s and I see easily how the 4:10’s and especially 4:30’s are overkill for a daily driver. One trip on the interstate will let you know…
Also on the 200rpm difference (I actually think it is a bit more) but to put that into perspective since I ride at 2400rpm at 70mph I run 2600rpm at 80mph but that is a "big" difference in the feel of the car. Just as well you will be even more limited with the 410's pushing nearly 3000rpm just at cruise Every time I drive on the interstate with the 373's I just can't imagine having 4:10's…
Again good luck with your choice
