[6D9]

Ok... the Currie 9" shows up tomarrow and my local guy is setting up a third member. I now need to make a choice on what rear gear to run.
It comes down to 3.50/3.55/3.70/3.73. The car will be driven on the steet alot but see some strip time as well. My goal for the car is to be able to 60 foot in the mid 1.6's and run high 11's. My dad seems to think the 3.50's and I am thinking 3.70's. The tires are 275/50/15 BFG dr's.

[67RS502]

There are guys on here running low 11s with 323gears and 406s, so I say go with the 350-355gear, you should be in the 11s no prob.

[RYAN c]

get another third and have 2..............

[jethro]

3.73

Flexible to both worlds, allows a lot of play later with upgrades/changes in tranny, engine, etc..

Wonder why my signature is not showing... if it did, it would list 3.73 gears in it.

[pdq67]

Ryan's idea hit it right on the head!!

Get two and go with a 3.00 and a 3.89!! One for the road and one ta turn the tires over down the strip..

I bet you can change them out in less than an hour if you practice some..

pdq67

[6D9]

I do plan to get two third's down the road. I will get the 3.0 for cruising . Do you think I will have tractions issues with the 3.73's/long stoke/smallish cam??? Also I know Eric 68 is flying with the 3.55's and has more cam and smaller motor....hmm. I just dont want to overgear it with the short 26" tires. Desktop says it peaks at 5400 rpm.

[Obxhokie]

6D9,

I am by no means an expert, but I have done a bunch of research since I have been working/changing my drivetrain. IMHO, 3.55 should be almost ideal based on your tire size. My rough calcs (correct me if I am wrong)with your tire size and a 3.55 rear have you going through the trap in the neighborhood of 115-120 with an ET of 11.3 to 11.8 seconds assuming 400 to 450 HP (again this was rough and quick, correct me if I made a mistake in my math!) Driver and traction variables were not included so don't hold me to it

My point is 3.55 is going to be a easier highway ride until you get the second third member. and unless you want to change the cam to peak higher and spin it well above 6 grand I wouldn't do the 3.73's. The 3.55's will also be low enough that if you want to switch to an overdrive tranny later you shouldn't be bogging the engine down in overdrive unless you are doing 90mph+

Anyway just my 2 cents, for what its worth.


Victor

[pdq67]

Back again.. I love my stock, 12 bolt's 3.31's!!

I can turn over a 25.5" tire great and go down the road fine with say 28" tall tire..

pdq67

[Obxhokie]

pdq67,

I really like 3.31's, I think there are an ideal street gear for a M20 with a 25 to 26 inch tire. My 12 bolt should have them in there to be correct but I couldn't get my hands on a new set when I had it rebuilt. I had 3.08's put in it but I wish I had gone to the 3.42 gear instead for a little more performance with my 26 inch tire. The 3.08's are nice on the highway though. My point was, between 3.55 and 3.73, with his engine, 3.55 was the better gear.

Victor

[6D9]

Thanks guys for the replys, Well I ended up going with the 3.55's. Should be just about right for my midrange motor with big cubes. Should be a bit easier to hook on DR's as well. Thanks again for all the replys...you guys rock!