ricekillman

Here is my delema. My stock rear is done. Pulled the cover, the pinion has no teeth. None! I'm getting a 12 bolt or a 9inch in three weeks. Which one should I go with. My plan is to later run slicks and maybe as much as a 150 shot. I ran a 12.95 at 110 with a 2.0 60' with the 4:10 in the stock 10 bolt. Now that I'm getting a new rear end, i'm stumped as to what gear to go with. I still want to hit 12.9s on drag radials NA, but I also want to spray on slicks. This would raise my trap too high I think for the 4:10. Could I run a larger slick and still trap in 4th with the 4:10s or do I need to drop down to the 3:90s. If I do would I still be able to cut 12s on drag radials? Help me out guys.

whitecamaross

get a 9 inch ford. dont make the mistake of getting a twelve bolt. they are known to break with good clutches such as cartek's. get a ford 9 inch with 430s and watch your ets drop to mid twelves. dont waste your money on a twelve bolt. they arent worth it.

Hardtop

iTrader: (3)

I had a 12 bolt. I now have a 9". Do yourself a favor and get a 9".

Bruce

SMOKIN01TA

iTrader: (10)

i think 4.10 are pushing it with a stock rev limiter. i went 114. could have gotten 116-118 maby with drag radials. id go lil lower if you are staying with tiny tires and shooting 150, but with 26" slicks with some decent width so they can grow on top end. you should be ok with 4.10s. they are definaly nicer for daily driving. just my 02

ricekillman

My rev limiter is at 6300. So thats 100 extra rpm and with the 4:10s and 26in et streets, spraying. Would I be able to trap over 120 before haveing to shift? If it get to it i guess I could get beffier spring and rev a bit higher like 6500.

SMOKIN01TA

iTrader: (10)

i dont think you will make it.
i would personally have to say no, i dont think you will go 120 with that setup. you would need either 3.73's, bigger tire or 6600 rev limiter to be safe imo. hopefully someone who has tried this setup will chime in and verify this.

ricekillman

I guess I could run a 27in tire but that seems way too big. Anyone????

soslo

iTrader: (12)

If I may suggest my own site for a calculator that may help...
Auto Formulas

Get 3.90s if you want to trap 120 (because your MPH is an average through the traps - you actually need to be able to go faster than you MPH on the timeslip).

Redlinez

iTrader: (5)

I know of someone who wanted a 12 bolt but got a Moser 9 instead. He had to cut, bang, and modify a lot of crap to get that "drop in" rear end in. You may want to consider a 12 bolt with all the best internals or possibly a 8.8 conversion. Not to mention, 9 bolts are power robbing rears unless you plan to go stupid fast.
Side note, I just ran 117.26 on 4.10's with kuhmo 711's shifting at 6500. Stock headed, stock ls1 intake, full weight ( I weigh 235 as well) car. Spraying may make you want the 3.90's though, if not 3.73's.

Savageite

Don't get a 12 bolt. It will break with that M6 and then you will want a 9". Trust me.

Navy David SS

iTrader: (13)

All I can do is relate my experiences.

Stock engine; stock 6,150 rev limiter; M6; McLeod single disc clutch; 12-bolt w/4.30 (this set up lasted 2 years, 350+ passes):

Engine only: 26x10x15 ET drags: best of 12.51 at 113 with 1.64 60'
100 shot: 28x10.5x15 ET drags: best of 11.38 at 124 w/1.50 60'

I narrowed my Moser 12-bolt by an 1.25" on each side. Both 26" and 28" fit great. No hammering, no trimming. The only thing bad about narrow the rear-end is getting the "normal" street rims to fit - so I just run the stockers with a couple of spacers. Go to my site and see how they fit.

SO, IMO 4.10's are just fine. I shifted at 6100 (both on engine and nitrous) finishing the 1/4 right as the shift light came on.

Good luck

David