Whats the best gear

**Jason915** · 12-10-2002, 10:43 AM

Thought I'd get a few opinions on what would be the best rear gear. I have 3.08's now when I install my Novi I will be going with a shorter gear but I am in between to choices, 3.55's or 3.73's. I have seen guys at the track running 3.73's and it seems like 1st gear can become a hassle because of the T-5’s 3.33 1st gear. Even with 3.73’s at 75 mph in 5th gear revs will only be 2500 rpms. I am wondering if the higher gear would be better for a car with stock heads and cam. But if I do a gear swap I want to feel a noticeable difference. What are you guys running with similar set ups?

**TheHawk05** · 12-10-2002, 12:05 PM

IMO if you are sticking with the stock 1st gear ratio, I'd go with 355's. My buddy has 373's in his essentially stock Stang and he hates them, first gear is useless. 327's would be a good choice as well if the car is strictly street driven as all the extra power from the Novi will pull that gear with ease and still spin the tires at will. 355's are about the best all around gear for a street car that goes to the track once in a while as it won't rev too high on the highway, 1st gear is still useful and the car will pull gears quite sharply with all that power you'll make. All depends on your intentions with the car.

**Jason915** · 12-10-2002, 08:33 PM

Thanks for the input Hawk, I drive the car daily and like to go to the drag strip in the summer with it a few times, sounds like 3.55 would be best

**UNTCHBL** · 12-10-2002, 09:17 PM

Jason,
I have 373 in my car, that have been there for a couple of years. While it was a daily driver even. I like em, and wouldn't change them for the world. I do however have an older tremec 3550 (I'm not sure what ratio it is in first) My engine is basically stock. This weekend I'll have my novi 2k install done, so I don't know how they'll be with the blower. Oh, I have 28 inch tall tires now, so That could be one way to slow the gear down. Just my 2 cents.

Brandon

**dmpmw** · 12-10-2002, 10:31 PM

The majority of the people that we install gears for or sell to choose 3.73's. I can only recall a very limited amount of people that have been disappointed in the gear, thier only complaint was............ not enough!!!!!!!!! They wanted more. 3.55's on the other hand, we havn't installed in over a year due to he lack of interest. So, my choice would definitley be for 3.73's

Mike

**fanglemeister** · 12-10-2002, 11:30 PM

I've run many gears over the years, from 2.73 to 3.73...

IMHO for a 99% street ride &/or open-track machine with a long runner intake that is done by 6k rpm, the 3.27 is hard to beat. However, if you want to "run your best number" in a drag race the 3.73s are the way to go. I've had 3.73s installed for a couple years now, they are fine for the street, with just a few issues to deal with-- You already know about 1st being overkill w/ 26" tires, and stoplight city driving is a PITA w/ all the shifting. The car won't mind cruising all day at 70 mph- the problem is with the top end speed. Remember that you must not use WOT in 5th gear! IOW if you want to go faster than say about 125 mph on 26" tires (6k redline) you really don't want the 3.73s. Taller 28" tires (275/60) will go a little faster practically speaking, and then that is that. Realizing, most street confrontations are finished by 125, I went with them. But there are some situations where you might want or need more. This is what I miss the most w/ 3.73s, not being able to accelerate hard right thru the 120s & beyond. Guess I need to build myself a 7k rpm bullet...

**NOVIGT** · 12-11-2002, 09:37 AM

putting 3.90's in mine soon. can't wait. i have the newer tranny though. not sure the difference. i was hearing the same thing about 3.73 and 4.10's for my ride, so i went in the middle. i'm glad the 3.90's were available. good luck in what you choose.

**Jason915** · 12-11-2002, 12:06 PM

Thanks for all of the input, dmpmw I will be installing the gears myself. I have had the axles out before to replace the outer seals and it looks just like a GM 12 bolt, I have never hung gears in a 8.8, but it I have in GM 12's, anything I should be aware of? Also I think I'll rebuild the Trac Loc and add some extra clutches in it, do you guys do that in your shop as well?

**CopMagnet** · 12-11-2002, 02:54 PM

3.73's in mine with the AOD.... happy with them, but the next step will probably be 4.10's and 28" tires once I up the power.

**TheHawk05** · 12-11-2002, 04:43 PM

Originally posted by dmpmw
The majority of the people that we install gears for or sell to choose 3.73's. I can only recall a very limited amount of people that have been disappointed in the gear, thier only complaint was............ not enough!!!!!!!!! They wanted more. 3.55's on the other hand, we havn't installed in over a year due to he lack of interest. So, my choice would definitley be for 3.73's

Mike

I'm assuming most of the guys you do installs for are Mustangs of the SN-95 variety with 4.6's as most fox stangs have gears already. For those cars I'd definately say go with a 373 as they need the extra pull that gear provides due to the soft torque those cars have compared to the 5.0 Fox bodies.

**Jason915** · 12-11-2002, 06:27 PM

Yea I know that the Mod motors respond to lower gears better than a pushrod engine, 3.73's should be the highest gear for them, I am kind of swaying twards 3.55's my car is allready much lighter than an SN95+. I raced a guy w/ a 95 GT the other night he had 3.73's and I have 3.08's he would jump in front of me off of the line but he couldn't pull away at all, he beet me with about 3/4 to 1 car length. I heard him get into the rev limmit in between 1-2 shift.

**TheHawk05** · 12-11-2002, 07:01 PM

Like I said, it all depends on your intended use for the car. Primarily street driven I'd say the 355's for a fox Stang. The SN-95's don't have that crappy 1st gear ratio that we do so the 373 works better for them. When you get on it in my buddies 86 in 1st gear, you're shifting pretty much as soon as you step on it. He doesn't even use 1st when he drives around as it will pull away in second no problem. Same thing applied when we did open track events with it (road racing), it always seemed it was in the wrong gear at given points on the track, buzzing in one gear and not enough RPM in the next. It's up to you and I'm not gonna tell you what to do with your car, just think about what you really want. Too many people fall into the "peak trap" I call it(always thinking peak HP numbers). It doesn't really apply with gears, but IMO far too many people worry about and are only concerned with peak power numbers, when you should focus on power under the curve. Example:

On another forum I go on, a guy was asking if a 75mm TB was too big for his non-blown street driven Stang. He didn't have a lot of motor work so I told him it was way too big. I told him even 70 was too big and to stick with a 65 as it will give him better throttle response and therefore better driveability. Needless to say I got jumped on by all the experts telling me I don't know sh*t, and that the bigger TB will give him more power at 5800++ rpm. Although that may be true, I argued he'd give up driveability and torque down low and besides, this was a street driven car, how long is this guy gonna be at 5800 rpm anyway? At most were talking about a HP increase he won't even feel. One guy even argued with me that a bigger TB will extend the power band of an intake, like if it was designed to operate from say idle to 5500, you could extend that by putting on a bigger TB. I have yet to see that one! This went on for pages and I was basically told I was wrong and should admit it since I was the only guy arguing it and so many were saying the opposite of me. Basically I told them to do whatever and keep reading and believing everything they read in the magazines. If you want to see a guy who did his homework with parts selection, look at the dyno graph for Dugscpe. This is what you get with a good package. Nice HP, but more importantly it's nice and straight with no big peaks or valleys and a beautiful fat and flat torque curve.

Best advice for car stuff: Use common sense

P.S. Sorry for getting off topic and for being so long winded

**dmpmw** · 12-11-2002, 07:21 PM

Originally posted by TheHawk05
I'm assuming most of the guys you do installs for are Mustangs of the SN-95 variety with 4.6's as most fox stangs have gears already. For those cars I'd definately say go with a 373 as they need the extra pull that gear provides due to the soft torque those cars have compared to the 5.0 Fox bodies.

Yes, mostly. Every now and then we get a Fox in there, but not often.
Jason915, we usually don;t rebuild the trac lok's we install a new Auburn if hte customer is serious, but if it needs it, we can do it.

**root** · 12-11-2002, 11:25 PM

I would go with 355's for sure, 373's would be better for an AOD.

Ian

**Jason915** · 12-12-2002, 10:29 AM

Thanks to everyone that had input, Hawk I cant belive some one wanted to use a 75 MM TB on an engine that didnt have much work done to it, I have seen 300 RWHP with a 60mm, he'll have no response and it'll bog like a dog off of the line. Oh well I will be putting in 3.55's shortley after the Novi install