Also, if you post your cam and intake specs, I'll be able to tell you where your hp/tq peaks will be. That will help in deciding on the overdrive ratio. Usually solid rollers give a hint that you're gonna be spinning the engine pretty high, but large a displacement will tame a large duration.

You will be fine with the 3.31 gear with the TKO 600 and .82 OD.

I have a TKO 600 (.82 OD) with 3.42 rearend (and a KC bored/stroked aluminum FE)--the comination works well (and I wouldn't hesitate for a minute to switch to a 3.31 rearend).

I'm happy my rear end will work out. ;)

Blykins- I haven't worked out the detail's with the cam. I don't think I have your 2nd email ?

Dave, the tire I have now is a 295/50/15
The Billboards I think,....are either 26.5" or 27". Which I have no idea what that converts to ? Someone here on CC, had a chart but, I don't recall who ?

I sent you an email on the gear ratios and the pricing on the transmission.

I'll send you a PM with it all.

Given a 3.31 rear ratio, .82 final drive, and a 27" tire you will turning 2195 RPM at 65, 2027 at 60. 26.5" tire height will yield 2237 at 65.

All things equal, with a 0.64 and a 27" tire you'll see 1714 RPM at 65 and 1582 RPM at 60.

The 0.64 will be useless for road racing..

That's the numbers I would be satisfied with for sure. Like I said, with my 3550 and 331 gears, I ruining 2,000 rpms at 60 mph.

The aluminum flywheel is a little quicker in 1st and 2nd if you have the tires to stick. It also responds to street surface variation for acceleration a bit better as the rotating mass is lighter. For 3rd and 4th there's basically no diffrence in acceleration.

The heavier flywheel will hit the next gear with that rotational energy harder to give a little push if you shift quick before revs drop. The transmission may not like the quick shifts as much with the heavier flywheel.

My Invoice from Kieth wasn't itemized, so I can't really give you any one part's cost.

Talk to Lance at KC and get an estimate, my package was a little over $27k, pretty good considering the upgrades (Shelby block) Mass-flo and driveline. I think the Shelby blocks have gone up again.:rolleyes:

I went with aluminum and am happy...flywheel cost me $80 used at the local mustang shop, resurface and match balance was $200, clutch was about $50 in the CC parts for sale section........Kid did the install for a chocolate milkshake. Just goes to show that these things don't have to cost a fortune. :)
http://www.clubcobra.com/photopost/d...s/100_1496.JPG
-Jon

funfer you will soon know what 600 plus will feel like keith did my 482fe on my kirkham and i have not seen this posted yet so let me (RESPECT THAT POWER BECAUSE IT REMINDS THE FORGETFUL ONES) breaking loose at 80 was soiled my undies

Yes, you absolutely need to respect the power--no doubt about that.

However, you might need to get some better tires (e.g., Avons, GY Billboards, drag radials) if you are breaking the tires loose at 80 mph.

I agree, most don't know how to respect power. Same with the sprints cars, especially the younger guys.

I'm now looking for prices on a new Tremec 600 to handle the HP/TQ.
I got a descent price from someone here for $2,095.

There's a Safety Aspect
 

An aluminum flywheel in a Cobra also lends a certain margin of safety. When you're moving up fast through the gears, a quick shift, at say 5500 RPM, into third will bust your tires loose a little faster with a heavier flywheel. A lighter flywheel will be slightly more forgiving -- sometimes you want that.:3DSMILE: Personally, I always prefer to be forgiven; especially in the Cobra... thank you very much.:p

Dave- "Given a 3.31 rear ratio, .82 final drive, and a 27" tire you will turning 2195 RPM at 65, 2027 at 60. 26.5" tire height will yield 2237 at 65.

All things equal, with a 0.64 and a 27" tire you'll see 1714 RPM at 65 and 1582 RPM at 60."

To save gas in 5th gear from 65 mph-75 mph and up, would the .64 be a better choice ?

A potential problem may be with my 331 gears on the highway at 60 mph, will the engine be running too high of rpm's for 4th gear, but too low for 5th and will be lugging ?

Like I said, 331 gearing, 295/50 tires, at 60 mph my rpm's are at 2,000.

These are quote's from another site. I don't understand with his taller gears, how he can have such low rpm's at the speed he's at ?

"I run a TKO-600 w/ 0.64 OD and 3.27 gears out back. RPM id 2100 at 75mph. My engine is a 427 Side Oiler, 10.6:1 CR, Edelbrock Performer RPM heads, single 850cfm carb, and a VERY heathy cam.

but 2100 @ 75mph while good for the hwy means that you rev up 4th gear for those 40-65 mph jaunts down back roads and traffic situations"

Another-

"I running a TKO600 with lots of h.p. With 370 gears in the axel my rpm's are at 2100 at 70 mph. in 5th gear. 125 mph at 4000 rpm. good luck."

Last example-
depending on camshaft you might want to think about a road race version tcet4617 for the 0.82 overdrive

some of the bb guys we sold to in the past had issues with the 0.64 od in that the car was doing 80-90 mph before they could really use 5th gear- either the motor wouldn't work down below 2500 rpm in 5th or they couldnt wind out till that speed to get it into 5th

also what rear end ratio are you going with i have some customers running 3.73 /0.64 od for a fix of above problem

this is a rare occurance but its something to concider before laying out the cake

if you have any ??s give us a call
FORTE'S PARTS CONNECTION
508-875-0016 "

Getting confused on which OD, .64 or .82 ?

I have the .64 along with my 3.54 rear. I absolutely love it for hiway driving. You can not use my fifth gear for road racing. But with my rear ratio, and the fact that my FE can run at 2000 RPM, it lets me go down the highway and actually hear my passenger. My other four gears take me comfortably to 140mph. :D My fifth gear is a single purpose tool -- it is for "leisure cruising" on the hiway (or, I suppose, for really hi-speed driving).

You should do something like this...
 

... before you decide on your ratios (trans & rear). You should also be familiar with the characteristics of your car in the 2000-2500 range (your engine builder should be consulted on that). A car that hiccups and bucks at 2000 RPM should not have a .64 fifth with a numerically low rear end.

http://www.clubcobra.com/photopost/d...hiftpoints.jpg

My gut feeling with your combo, the small mechanical roller, 482", Victor intake that with your 3.31s, 26.5" tires and a 0.64 overdrive your engine's not going to like to cruise under 75+ mph, maybe 80. That's just 2014 rpm at 75 mph with a 0.64 overdrive, 2533 with a 0.82. With the 0.82 you'll be able to sustain a 65 mph cruise at 2200 rpm, very doable with your setup. If your tire height is 27" it's even worse with the 0.64. I also think that you're even going to get some bucking at the 0.64 cruise RPM with what you'll be running. Take my advice and get the 0.82s and never look back. I'm sorry I didn't, but am not willing to spend the $$ and time to switch out my 0.64 TKO 600 to the 0.82 at this time.

As Patrick said, confer with your engine builder (Keith) before you make any decisions. I'd even pose the .64 or .82 question to him.


Dave

Sounds good guys. I want everything to work in synchronization.
I intend to ask Keith about all the drive line, and this has been a great precursor for my build.

funfer my combos are 3;31 rear toploader from david kee and i love it by the way i have a jag rear for sale with 3;31 new its posted on club cobra if your interested but i think you have astraight axle