newcastlegreg

Gosh this 5 speed thing is sure a dilema for me!! What a big decision...I am doing a body off frame BB coupe with a zz454. The differential is apart and I did some trans/dif calculation on the trans gearing calculator website. If I use my m-21 and put a 3.36 rear end My cruising rpm will be 2825 at 65mph. If I go the 600r tremac with a 3.70 rear which they recommend my cruising rpm at 65 will be 2551-only 274 rpm less...Now I realize the burnout factor will not be as good on the other end. However the motor I am using has good torque with a mild cam. I love the 5 spd but over many years of owning these cars It seems like I am always doing something either to the clutch, flywheel , trans and engine seals, clutch forks, bearings. My point is the 5 speed just seems so tight-and I think about havivg to pull a 454 with power brakes, steering and vintage air over a new paint job if stuff screws up. Your input would be greatly appreciated in helping me make this decision. This is a tough one just like the vintage air decision. Thanks

midyearvette

go ahead with the swap you won't regret it...i have the 454 ho with a tremec.....082 od and i love it...im glad i did not go the .062 as it would have been too tall for any kind of performance in 5th gear. i also have a 336 rear......fyi....watch oil pan clearance to the road here...the 6 quart pan is lower than the stock big block ........2500 rpm is 75 mph with 235 15 rear tires...good luck also grind the ridge off the top dust cover on the tranny on the passenger side!! do it now!!

muncieman

I like the .062 with more gear out back. But I'm a small block guy or 427 person and they can stand the rpm better. I just like the gear multiple of say a 4.10 and the 5 speed

Cruise will still be in the good range.

C2Driver

Greg, I think you should consider the .64 O/D with the 3.70's. As you have noted yourself, the .82 O/D Tremec at 65 mph will only be 274 rpm less than what you have. I've got 3.70's with the ZZ4 in my '63 and I'm running the .64 O/D. Gobs of torque in 5th and I run around 2000 RPM at 65 mph. My 2 cents.

Check it out on the Speed Analyzer:

http://www.keislerauto.com/speed_analyzers.php?sa=gm_5



- Pat

Kensmith

Greg,

I have a 350/370 solid lifter motor in my 65 coupe. I have the TKO 600 with .64 5th gear. I have had 3 different rear ends in the car, 3.55, 3.70, and now a 4.11. I LOVE the 4.11 with my high winding small block. BUT, with a big block, not sure that would be what you want. I cruise on the highway at 70MPH taching 2400RPM. My problem with the 3.55 was too low RPM at highway speeds. 3.70 was not too bad but the 4.11 seems perfect for me.

1snake

The trouble with 3:70 gears, 1st gear (2.87) in the TKO 600 is basically useless. It's the same 1st gear ratio as a M21 with 4.56 rear gears. If you check out other forums (Hotrod, Cobra, etc) you'll find the vast majority have the .82 fifth gear with a rear ratio of 3.08 - 3.36. I'm running a TKO 600 in my Cobra with the .82 5th and a 3.27 rear gear. 420 HP & 410 TQ. Still no traction in 1st but 5th gear is perfect on the freeway.

Jim

C2Driver

Jim, I have to agree that I'm not in 1st gear too long, but man does it haul before that quick shift into 2nd. It screams off the stoplight.

- Pat

midyearvette

wrong math.....if 2825 is your present cruising rpm then the .082 will knock it down by approx. 20% or 560 rpm to approx. 2225 rpm i think .......did it in my head so check it out on a calc.......

1snake

I can boil the tires in 1st at will but I'm also 1000 lbs. lighter. When I drive my 60 with a T-10 and 4.11's, I'm always reaching for 5th. That combination sux, especially on the freeway.

Jim

Kensmith

I have to disagree with you. I had the 3.50, 3.70, and now 4.11 with the TKO 600 .64 5th and I love to death 1st gear pulling form a stop. Freaking crazy fun!!!! But then I also like shifting gears and I know some of the guys don't. I also have a SHP motor that will wind up to 6500RPM. So I can get it up to 45MPH in 1st if I want but I usually shift at 3500RPM or 25 MPH. Nothin wrong with a little whiplash is there?

newcastlegreg

This is the website I used to compare a 4spd muncie with 3.36 rear and a 5sp .82 and 3.70 rear end- only 274 rpm dif at 65 with 26 inch tires
http://www.stl-vettes.com/65Vette/Tr...ns_Gearing.htm

1snake

All I can say is the ratio that you're running is great for heavy or under powered cars. Your 1st gear is the same as a M21 with 5.13 rear gears. Good for the 2nd stripe of the crosswalk, nothing more. Run whatever you like.

There's a reason that the .82 tranny's were back ordered for months and that Tremec was considering a retro fit kit to change the .64 to .82 due to the overwhelming demand.

Kensmith

I'm not going to argue. But, I have tried all 3 rear ends and the 4.11 is by far the best with my car. You can run all the gear calculators you want but the best test is in the seat driving. My car is in no way underpowered and will outrun a big block anytime. Maybe those guys at the drags running 4.56 don't know anything? I switched to the TKO 5 speed for FUN and cruising on the highway. Fun pulling from stop and going through the gears, then cruising at a nice RPM on the freeway.

1snake

And they drive those cars on the freeway too. I've been building cars for over 40 years and owned a dozen C-2's, both big and small block, not to mention the many others including a LS6 Chevelle that turned high 10's.
I realize this is your first Corvette so I don't want to argue either.

67-427ci

I have a TKO-600 in my 67 Coupe with a zz454, power brakes & steering, Classic Auto A/C and 3.70 rear end. 70 MPH gives you 2,100 RPM. While it is a tight fit, it certainly is worth it if you plan on any kind of serious cruising. I was on a 33 day 8,000 mile cruise last spring. I don't think it would have been as much fun without the 5-speed. 1st gear is like a 4.24, 2nd & 3rd are about the same as a M21. Keep the 3.70 rear end and go for it!
Roy

newcastlegreg

OK now I am more confused on this possible 5 spd convert. Both classic chevy 5 spd and kiesler reccomend the .82 600 and a 370 rear for my BB--Originally I was going to do muncie m21 and 336 rear- if you take those two and compare the 5 speed runs at only 274 rpm less at 65 mph. So???

1snake

While I agree 100% with the .82, I would go with a 3.50 max. and preferably a 3.36 rear end, especially with BB torque.

midyearvette

works great in my car, the 3:36 i sent gregg a pm told him to come over when the weather breaks and i will let him drive me around in my 66.......good luck to all

Kensmith

My point was with a 4.11 or even 3.70 rear and TKO 600 with .64 5th gear you can do both. Drive the street and drag strip. Best of both worlds. Yep, 1st Corvette, but not first classic, streetrod, hotrod, or other car with manual transmission. That's what is great about this forum, lots of different opinions to choose from. If the weather is nice, I will be taking Greg for a ride since he lives close to me and he can get an idea even though he has a BB car.