CorvetteForum - Chevrolet Corvette Forum Discussion

CorvetteForum - Chevrolet Corvette Forum Discussion (https://www.corvetteforum.com/forums/)
-   C3 Tech/Performance (https://www.corvetteforum.com/forums/c3-tech-performance-3/)
-   -   Which Clutch Kit for a 383?? (https://www.corvetteforum.com/forums/c3-tech-performance/2967132-which-clutch-kit-for-a-383-a.html)

BigBadBorry 12-16-2011 02:09 AM

Which Clutch Kit for a 383??
 
Greetings fellow C3'ers,

Over the Christmas break I shall be replacing the existing 350 in my '70 'vette with a 383 rated at 440hp.

Question: I will be using an 18lb flywheel, so which clutch kit will serve me the best? I've seen a multitude at Summit but first hand experience from you guys will help guide me along.

Size and style to handle the horses???

Thanks,

B

73, Dark Blue 454 12-16-2011 05:54 PM

I like the CenterForce DF (dual friction). Has 90% more holding power than stock (according to CenterForce) and the clutch pedal is as easy on your leg as a new Toyota.

I'd go with the 11" set up which means you need a 168 tooth flywheel (14") and the larger bellhousing and "offset" starter (has offset mounting bolts).

cv67 12-16-2011 10:46 PM

Centerforce DF here also so far love it. :cheers:

spdrcr29 12-17-2011 12:40 AM


Originally Posted by BigBadBorry (Post 1579485741)
I've seen a multitude at Summit but first hand experience from you guys will help guide me along.

Size and style to handle the horses???

Thanks,

B

What do you guys think of the Ram (Musclecar, Powergrip, Force 9.5) or Zoom (30000 Series or High Performance) Clutches that Summit has to offer?

BigBadBorry 12-17-2011 08:09 AM

Followup question...

How do I determine (prior to dismantling) flywheel tooth size and clutch disk size ie 10.4 or 11" - 10 spline or greater??? I'd like to order parts beforehand but not sure if this can be determined at this point in time...

gkull 12-17-2011 09:23 AM

What kind of transmission do you have? I use a Protorque 3.1 hp mini starter. I use the 168 tooth. Your 350 came with a 153 tooth. So if you want to keep your starter you need the 153.

As for fly wheel weight. If you have a heavy crank and damper you can use a 15# fly wheel.

Most moder hi performance clutches are easy on the leg pressure.





http://www.summitracing.com/search/B...?Ns=Rank%7cAsc

69 Chevy 12-17-2011 09:35 AM

168 teeth ring gear=11" clutch

153 teeth ring gear=10.4" clutch

You can tell whether you have a 10 or 26 spline input shaft by unbolting the driveshaft and counting the output splines.

27 spline output will have a 10 spline input.

32 spline output will have a 26 spline input.

BigBadBorry 12-17-2011 10:45 AM

Thanks for the tip on how to determine.

I'm guessing that the flywheel will need to be rotated manually without starter in position and count 'em that way?

BigBadBorry 12-17-2011 05:35 PM

Thanks gkull and 69 Chevy, very helpful info you have provided.

She's a 4 sp but again not sure how to determine if it's an M20 or M21. Knowing it's a 153 flywheel now provides me with the opportunity of ordering the parts and having them arrive same time engine does - it's currently on the water in transit to Oz.

69 Chevy 12-19-2011 09:01 AM

http://i3.photobucket.com/albums/y57...hwideratio.jpg

As long as the guts inside haven't been changed, you can tell close from wide by deciphering the code on the trans like mine from above.

The last letter in the code line:

A=M20 wide ratio
B=M21 close ratio
C=M22 close ratio HD 'rockcrusher'

You could also put the trans in first gear, mark the flywheel and driveshaft/output yoke. Wide ratio M20 has a 2.52:1 ratio while both the M21 and M22 close ratios have 2.20:1. Flywheel will either turn 2.2 or 2.5 revolutions for 1 revolution of the driveshaft. That's a positive way to know short of removing the sidecover and counting the mainshaft gear teeth.

BigBadBorry 12-20-2011 05:49 AM


Originally Posted by 69 Chevy (Post 1579510260)
http://i3.photobucket.com/albums/y57...hwideratio.jpg

As long as the guts inside haven't been changed, you can tell close from wide by deciphering the code on the trans like mine from above.

The last letter in the code line:

A=M20 wide ratio
B=M21 close ratio
C=M22 close ratio HD 'rockcrusher'

You could also put the trans in first gear, mark the flywheel and driveshaft/output yoke. Wide ratio M20 has a 2.52:1 ratio while both the M21 and M22 close ratios have 2.20:1. Flywheel will either turn 2.2 or 2.5 revolutions for 1 revolution of the driveshaft. That's a positive way to know short of removing the sidecover and counting the mainshaft gear teeth.

Thanks. I was under the car tonight and I can see a casting number on the side 308833 (??). Where is the stamping located? On top of the tranny?? The 308833 does not feature in a Google search.

69 Chevy 12-20-2011 10:01 AM

ID code is located on the right side main case, running vertically just in front of the mid bearing as seen in this pic of my '69 Muncie.

http://i3.photobucket.com/albums/y57...eIDlocator.jpg

DRIVESHAFT 12-20-2011 10:08 AM


Originally Posted by spdrcr29 (Post 1579493734)
What do you guys think of the Ram (Musclecar, Powergrip, Force 9.5) or Zoom (30000 Series or High Performance) Clutches that Summit has to offer?

I'm using the Powergrip and haven't had any troubles with it.
The pedal isnt too stiff, it hasnt chattered at all, and even though I'm running a healthy big block and drag radials the clutch hasnt slipped.

spdrcr29 12-20-2011 01:20 PM

That is good to know. I was considering the Powergrip, but also the Force 9.5 (but I think it may be overkill). I also considered the Centerforce, but the local speed shop says they remove the balance weights because they make noise?? Thanks for the input. Not quite ready for a clutch, but just thinking ahead....

BigBadBorry 12-20-2011 03:18 PM

Thanks 69 Chevy - gives me another reason to get down and dirty under the girl tonight.

BigBadBorry 12-23-2011 03:02 AM


Originally Posted by 69 Chevy (Post 1579519559)
ID code is located on the right side main case, running vertically just in front of the mid bearing as seen in this pic of my '69 Muncie.

http://i3.photobucket.com/albums/y57...eIDlocator.jpg

Well got down and dirty with the girl and she reveals her details as:

POB030A February 3rd Production and an M20.

Even though she's an early 70, and most likely a 10 spline input, I'll take your advice and drop drive-shaft to count the output splines.

And good news also, she is a matching numbers tranny...

Thanks :)

69 Chevy 12-23-2011 08:55 AM

I would be surprised to find a numbers matching 1970 Muncie to have a fine spline OEM input shaft. Although, unless you know your car's history, things could have been changed in the last 42 years.

Mine started out as an M20 but I installed replacement gears years ago to make it an M21. No one can tell from just looking at the exterior.


For the 1970 model year, there were two major changes to the Muncie four-speed. In previous years only the M22 transmission had a drain plug, however, beginning in 1970 all Muncie four-speeds now had a drain plug. The second change was the addition of a fine-spline output transmission assembly for only the Chevelle M22 applications. This required use of a new tail housing, which was specific to the Chevelle M22 applications for the 1970 model year. All other transmission assemblies including Corvette used a course spline output shaft. The 1971 model year marked the last of the major changes to the Muncie four-speed transmissions. The input and output shaft both changed from course spline to fine spline. This carried over for all Muncie four-speeds.

cv67 12-23-2011 09:57 AM


but the local speed shop says they remove the balance weights because they make noise?? T
More idiots :ack:

They dont make noise, leave them in there.

BigBadBorry 12-23-2011 10:09 AM

Thanks 69 Chevy, I think that I can safely place an order with Summit for a Centerforce DF271675 kit and have it Fedex to Oz. Delivery will coincide with my 383 :) - I'm getting very impatient...

MotorHead 12-23-2011 11:24 AM

I have had the same Centerforce DF in 3 motors, 400hp 350ci, 550HP 406ci and my current engine and both the 406ci and my 427ci you are looking at 500-600ft/lb of torque. Ask that "mechanic" if he can store the wieghts for you where the sun don't shine :cheers:


All times are GMT -4. The time now is 05:38 PM.


© 2024 MH Sub I, LLC dba Internet Brands