What Trans Do You Have & Why ?
 

I've had the older Tremec 3550 5-speed, and liked it and had no issues. I also enjoyed the overdrive gear.

What do you have and why ?
Likes & dislikes ?

I have a Backdraft Cobra with a Roush 427R (550 HP) with a 6-spped manual Tremec T-56 tranny. Great tranny! I cruise around town in 4th and 5th gears and freeway driving in 6th gear with RPM at 2000+/-. Gear 5 really helps the town driving at 45 MPH. My former Backdraft Cobra had a 5-speed Tremec. So, for my experience with the 5-speed vs the 6-speed. I find the 6-speed much more aligned with my driving conditions which is street and freeway driving--no racing, no driving in the rain or snow and no smoking the tires. GEE, if I sound old, I am. My Backdaft Cobra is just 2 years old with 1200 miles on the speedo. The car is garaged with my other toys. The car will be a great home someday to the new fortunate owner. PHIL

I also have a T56. At first I thought it was a bit of a waste, but now, i could not imagine driving without it. With 3.70 gears and 26.5" tires, I pull around 1900 RPM in 6th.

I own a TKO long time ago. Hard to shift so I bought a high dollar shifter. Helped a little. I did not like the 3.27 first gear. Sold it and bought a TKO 600 with a 2.97 1st gear. Lot better but still hard to shift. Put about 30,000 miles on it before I pulled it and put in the Liberty Gears street upgrade. WOW what a big difference. Smooth as a wore out T-5. Could not miss a gear.

I have driven a couple of 3550s. One in a 530 hp 408 for a total of a couple of thousands of miles. Never spun the rear tires. I know, that was hard.:)

The other Cobra with the 3550 has a 487 K.C. 620 hp side oiler. I've put a few thousand miles on it through the years and I've spun the tires a few times. Both 3550 are smooth shifting, easy to drive trannies. I would highly recommend the 3550, out of the box, over the other Tremecs that I have driven.
Now the 600 with the upgrade has to be the best.

Dwight

I'll add that the rear end ratio, tire size and cam all play a big part in how a Cobra drives with what ever tranny.

A motor with low end torque makes the car more street-able. More fun:)

t5z. Cheap, smooth shifting, lightweight.

I have an older 3550 TKO and it's just ok. Shifting is a bit mushy with occasional missed 3rd/5th shifts. With the 3.73 rear, the 0.68 OD is too tall for the motor (a bored/stroked 351 418 CI with a Victor Junior intake), as the motor wants >2000 RPM to cruise, which is ~75 mph in 5th.

My new car will have a TKO 600 Road Race with a 0.82 5th and 3.31 rear which should give me right at 2k RPM at 65, which I think will be perfect for the 482 with mild cam and dual-plane intake (loads of low-end torque).

I had a TKO 600 with the .64 overdrive. Hated it. Shifted like a truck and the rpm drop between fourth and fifth made fifth only suitable for high speed (80 mph +) cruising. Can't tell you how many times I missed third gear trying to speed shift from second.
Dumped it and bought one of Levy's super alloy T-5 trannys with a .80 fifth gear. What a difference. Shifts smooth as a normal T-5, easily handles 500+ horsepower, never miss third gear and now I have a useable fifth gear. With my 3.46 rear end and streetable engine, I should have bought this one first.

TKO600RR. The road race version has a gear spread that covered all the basses for me. No super low first and no ridicules OD (.80) that made everything from cruising to open tracking easy with a 500hp big block.

Close ratio top loader, vintage racing rules require it. Will let you know how it works once I get the car on the track. Just dry fit it on the engine while waiting for the roller to get back home.

I liked my cr toplaoder but with a 3.70 rear freeway speeds were screaming with RPMs. I switched to the TKO600 w/ .82 5th. Cruising the freeway is so much better at around 2000 rpms, but all the fun remains between 1-4th. 1st could be a little taller but I'm happy.
John

Have a TKO600 with the .82 5th gear, 3.54 rear axle ratio, using GM Synchromesh fluid, shifts well even with the stubby little shift lever in a 289. I like the spacing of the gear ratios and the .82 is nice step from 4th, the .64 would be too tall in my opinion, especially for a 289 / 302.

First up - I'm still building the car so it's all theoretical at this point.
I'm using a WR Toploader and a 2.92 rear end with my mild tune 302W. The car is very light so I'm not anticipating any problems off the line, and I just like the idea of accessing 60mph in 1st gear. Highway cruising will be easy with the high rear gears.

Cheers
Glen

I have the TKO transmission with a 2.95 first gear and the .68 fifth gear.
The first gear is lower than the 2.87 first in the later TKO600, so a 3:31
rear was selected to make first gear more usable. The first 4 gears feel like a
proper 4 speed sequentially, but the tall fifth is way out of sequence and only
useful for the highway. This is great for 80mph quiet cruising when you are
stuck on the freeway. Most of my driving is in the first three gears with fourth
gear less so...otherwise I'm way over the safe speed for West Marin roads...
and the speed limit. This combination was the choice of the builder but I do
find it quite useful to have the "freeway option."

I'm a T-5 fan. Light weight, strong, versitle and parts are readily available if needed.
Larry

Borg Warner T10L, aluminum case and tail shaft, because that and the iron case and tail shaft T10B transmissions are what came in 260 / 289 Cobras. I am also running the "L" gear set but I may try the "M" gear set at some point.

My first ERA I had 428SCJ with the big input 29" trans from a drag pack Torino. Because it was a close ratio I needed to switch to 3.73 rear. This time around I have wide ratio trans (24")with 482 fe and 3.31 rear and for my driving the setup seems perfect. Knowing that the 29" trans fit without problem, I think that if I needed a change,I would bolt a Gear Vendors unit on the back of the 24" trans and have every combo for every occasion .

I'm hoping,.....in two years, after paying off some medical bills, that I can either build another engine (after eight years of my Cobra sitting in the garage with no motor) or build one.

I've always felt that no engine will be in my Cobra other than an FE. I'm doing a lot of research, but what I'm finding is that even a 428FE is getting harder to find. The 427 aluminum side oiler done the way I want, is 17-20k to buy and apx 15k for me to build.

So, I'm checking into a 358 series, 460/514, as it's lower in cost and a HUGE cost and power difference,.....vs a FE, original or new. For apx 14k, I can have a 514 with 700 HP/TQ.
To have a 700 HP FE, like 28k (+)
.
Anyway, if I go with the 514 I will need more than the 3550, so that'll mean a stouter tranny.

My Cobra is a Lonestar which is a 94" wheelbase and set up for the Tremec 3550 TKO and 428FE.

The extra 6th gear would be very nice on the highway and interstate.

Is the other Tremec's longer ?
Shifter locations different ?
Tranny crossmember different location ?

I'm a retired dirt sprint car racer, so I need power, 600-700 HP/TQ. My driving style is mixed fun. :cool:

What's your thoughts on a tranny ?

I'm running a Richmond Street 5 Speed behind a 460 CID BBF, Final Drive Ratio (FDR) is 2.75:1.

As you can see by the chart below, the Richmond Street 5 Speed is a close-ratio transmission, with a gear spread of only 3.28:1. There's certainly an argument to be made that I don't need a close-ratio box behind a BBF, but I certainly don't need a lower 1st gear (higher numerically) to launch the car. Similarly, I don't need to drop the highway RPMs much, though a little wouldn't hurt (2328 RPM @ 65 MPH with 275/50R15" tires). Switching to 275/60R15" tires would drop the revs about 200 RPM at 65 MPH, though also making 1st gear slightly taller. Hmmm....

Interestingly, the Street 5 Speed is no longer available, having apparently been replaced by the Super Street 5 Speed. The closest box to what I have would be the 2.89:1 1st gear model - that would require a change of the FDR to 3.50 to maintain roughly the same 5th gear RPMs.

Transmission and FDR selection are about what you have and what you want to accomplish. Pick your transmission (and ratios) based upon your engine (torque and where produced in power band), then pick FDR. If you've got a high-strung small-displacement engine you'll probably be much happier with a different transmission than you'd put behind a mildly tuned big block torque monster. YMMV

http://i.imgur.com/0hgoEE5.png

The spread between the two company's is quite a difference.

With the power of the 514, the stock 1st gear of my 3550 would be usless off the line. It already was with my 550 HP 428FE, so depending on a few situations, I'd start off the line in 2nd gear. If I can get the first 4 gears as a close ratio for racing, the 5th & 6th gear can be for overdrive.

Which 460 etc do you have ?
What's the HP/TQ numbers ?

$3,500 bucks for your Richmond ?