OnyxCobra

definitely post some pics when she's back on the road

CrazyCobraSpeed

+1 unless you setup for 6.5K dont run it.... ull kill you spring/pushroads/lifters..... plus unless u have a higher rev cam u wont get nething outta the extra 500-700 RPMs... besides a headache and a f*cked up top end....


mustangs dont have governers.... actually a lotta cars dont... is just bs ppl talk about... u do have a rev limiter tho.... governer controls top speed rev limiter controls the RPMs which u can run up too....


as for hte question id go for the 3.90 outta the 2 choices.... if i have 3.90 and i do run to 6.5kRPM i could hit 123.9MPH i have 295/30/18 for tires.... if all u ever wanna run is low 12s thats good ez.... but u wont wanna stay at 12s forever... and ull need more top end to get go ne faster

here is a calulator to help u decide http://www.kabamus.com/garage/gears.html its pretty ez to use and understand

OnyxCobra

Crazy your tire is a little small too

gjmack3

I think you're going to hate those 3.90's. They are very,very noisy!! My friends cobra has them, and it is almost impossible to carry on a conversation on the freeway at 70 mph because of the gear whine. The gear is setup perfectly in the rearend. Backlash and pinion depth are right on. The shop that did the install says that particular ratio just makes a ton of noise no matter what. Just my 2 cents.

reno27

does the whine really matter is that bad or it just whines no matter what

94StinkinLincoln

no they lied to him...they f'ed up on the install. if done right none of the gears wine, ratio has nothing to do w/ it!

ih8chevy

whats ur cam setup? 410's would be good for something hitting in their power band at anything above 2600 rpms, anyhting lower and u go wit a higher gear.