What Gearing to go with? - Third Generation F-Body Message Boards

87mtl_bird · 11-06-2009, 07:13 PM

Hi Guys,

I have a question for all you knowledgeable F-Body guys. I have an 87 Trans Am with a swapped 4 barrel 350. Over the winter I am going to start building the motor (trying to make about 400hp). I want the car to be able to run a pretty quick time in the 1/4 mile, but still be able to drive it on the highway without being at crazy high RPM's

What gearing would you guys suggest? And if you can just explain why as opposed to another gearing.

I appreciate anyone's help with this

Cheers

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MADMAXGTA · 11-06-2009, 07:14 PM

what rear is it? and what gear does it currently have?

87mtl_bird · 11-06-2009, 07:29 PM

When I got my 350 swapped from an 86 Maro, the guy who did the swap, swaped over the differential as well, which I believe was originally from a Maro with a 305. I know that right now my diff is not posi, and the rear end is drum brakes. I plan on swapping to a GTA rear end with the disk brakes as well over the winter. I'm not sure what gearing it currently has...

Hope this helps

MADMAXGTA · 11-06-2009, 07:35 PM

Well you need to find out what rear end you will be going with,Ive had a few and though 3.70s/3.73s were pretty fun,however maybe youd like a 10 bolt 3.42 with disc brake to start with a very common rear end for irocs and gta.cheap to

whats your budget?

MADMAXGTA · 11-06-2009, 07:38 PM

maybe a 4th gen rear? thats a bolt on and you can then run 4th gen wheels

87mtl_bird · 11-06-2009, 07:51 PM

Based on what your saying I think I would go with the 3.42. I plan on hopefully finding the rear end assembly either at a scrap or used. As far as my budget is concerned, I think I would be willing to spend up to about 500 on the used rear end assembly.

So if I get what your saying, 3.73/3.70 is a better choice from a performance standpoint to run good 1/4 mile times, as well as quicker on the street.

But from a budget standpoint the 3.42 is a much better bang for my buck, and still provides fairly good performance?

This might be a stupid question but the difference between the 3.73 and 3.42 is what? Is the 3.73 shorter (therefore I would assume quicker)

Thanks for all your help man, I really appreciate it

MADMAXGTA · 11-06-2009, 07:54 PM

yup ,quicker,youll have a bit higher rpms at speed.Ill look around 500.00 is enought to get a NICE one.ive seen 3.42 go for around 150.00 plus shippping and thats gona be the killer unless your in a city with boneyards,im in the sticks...

MADMAXGTA · 11-06-2009, 07:57 PM

I found one on ebay just now.

87mtl_bird · 11-06-2009, 08:00 PM

I'm located in Montreal QC, Canada... there definately aren't as many F-Bodies around here than in the States. I have tried several times to get parts at the scrap... but most of the time when I call... they just tell me they don't have any maro's or trans ams...

I really appreciate your help and information man. If you do find anything let me know, but just the info you've provided has already really helped out

Thanks

87mtl_bird · 11-06-2009, 08:01 PM

Quote:

Originally Posted by XxCoLTxX

I found one on ebay just now.

If I use a 4th gen one though, can I still rock my GTA Mags... or is it a different bolt pattern?

MADMAXGTA · 11-06-2009, 08:06 PM

yea..But they would stick out farther.alot of guys would swap to 4th gens rear in your situation then get wheel adaptors for the front and run 4th gen style wheels zr1/ws6 and the slew of after market ones,but its all what you wana do.whats your ideal end result? got a pic?