hotrodstingray64

Hello, great forum. I have read alot and have learned alot from this forum. I have a problem. I have a 64 vette and my muncie is getting almost impossible to downshift. I am looking to swap out for another muncie but thinking of installing in a 5 speed. I have read about different setups. The tremec and the world class. I do not have the original engine but a later 327 that is stock so normal amount of power. My friend that will be doing the install says the T5 world class will be easier to install just need to find the correct hurst shifter. Any advice to keep the muncie or go with a T5? or would the tremec from a mustang and find the right adaptor be a better fit? Are there any postings or sites that explain the install of a 5 speed? thank you everyone

Bluestripe67

This subject has been discussed numerous times here. Have you done a search? Have your shifting problems just occured? Checked the fluid level? Any idea of milage on the trans? Is it only grinding when down shifting? Have you done the basic check of all the shifter linkage? You say the engine is "stock so normal amount of power". That doesn't mean much. You need to consider your rear gear ratio (if known) when picking a 5-speed. I'm sure others who have done swaps will add to this. Dennis

Tom Austin

YES . . . there are lots of post about installing a GM World Class T5 in a C2 . . . here's mine:

http://forums.corvetteforum.com/c1-a...tall-done.html

Good Luck!

Tom

hotrodstingray64

I found a tremec pretty close by that will be taken out of a running 70 Camaro hooked up to a 305. Buying it for 550 with everything included. My rear is stock at 336. not sure if I will need to change it out to something else to make it more drivable. What would be a better gear to use? My 327 probably is around 250 to 300hp. Thanks Sam

wmf62

wellllll, depends on what you are trying to accomplish... if you are just replacing your worn out muncie, then try the 3.36 first; if you have plenty of lowend torque then OD should be able to pull the 3.36 ok.

i have a 3.36 with a .72 OD, which gives me an effective rearend ratio of about 2.42. i have run the combination with a LT1 engine (which has NO lowend torque...) and the present ZZ4; both engines were happy...

if that deosn't work for you, then i would suggest a 3.55 or no more than a 3.70. try your present rer first.
Bill

hotrodstingray64

Trying to do as much research. Would I have to cut the cross member for all 5 speed installs? It wouldnt be my first option. Would this hurt the value of my car? It doesnt have the original engine so it loses the original value. Thank you for all your advice. Sam
My cell is 386-216-3763

Tom Austin

NO! . . . the main objective of my T5 installation was not to have to cut the crossmember. Mission accomplished!

Tom

MikeM

I would do a cost/benefit analysis and then go from there.

You can fix the Muncie a whole lot cheaper than you can swap in a five speed. Weigh that against any advantage the five speed may give you over what period of time.

MarkC

I put a TKO 600 in my L79 66 with a 3.70 gear. I consider it the best upgrade you can make. My old m21 needed work so I just went with the 5 speed. The Muncie can be reinstalled latter if necessary. I drive my car 12 months a year. In 2 1/2 years I have over 9000 miles. If your driving habits are local with limited interstate use, I would stay with the Muncie. If you frequent the interstates and travel with the newer vetts, you will love a 5speed. My car with the Muncie and the 3.70 gear was turning 2800 at 60 mph. You car with a 3.36 should be around 2400. My car now at 60 is about 1800. The TKO 500 may work well with your 3.36. The gearing in the 500 works best with a 3.08 or 3.36. IMO, the 3.36 gear is perfect for the M20 for mostly local driving. The M20 has the 2.54 first gear.

hotrodstingray64

Thank you for all the responses. I normally do local drives around town and some 50 or 75 miles runs down to Daytona but not much more than that. I was thinking because if I need to repair the muncie due to not being able downshift it would be a great time to add the 5 speed. I can get a whole set-up out of a running car (1970 Camaro) for around $500. Not sure what other parts I will need? most likely modify the driveshaft and cut the frame (which I think will lower the resale value which I do not see that happening in the near future but you never know) Thank you all for the great advice. Back to thinking about the best options. My wife will be driving the car also so I know she would like the ease of a 5 speed trans vice the muncie which feel pretty rough. I will look at the pros and cons again.
Quick question... What other parts would need to be bought if I use everything from the camaro tremec. The owner said it would be a straight forward install except for the frame being cut. Thank you Sam

DucatiDon

I swapped in a Keisler RS500. I have been very happy with it. The kit is a little more expensive that finding a camaro tranny, but it made for a very quick swap.

MikeM

If the Muncie shifts like it's supposed to and you are using a STOCK shifter that isn't worn out or dirty, it should shift smooth as butter.

If your transmission has a Hurst shifter on it now, I can see why a female would complain about stiff shifting even if the transmission works as it should.

MarkC

Sam, I bought my TKO from American Powertrain and I am pretty sure their instructions for the install are on their website. This is not an easy install. I had a racing shop install mine and it took them 14 hours and they said they don't want to do another. With a removable crossmember it is pretty easy. You will need a new clutch disc (I replaced the entire clutch ), trans mount, driveshaft and speedometer hookup. American Powertrain sells everything in a kit so you have all the parts. BTW, they say they can do the install in 6 to 8 hours. Also, $500 sounds cheap for this trans, I suggest you make sure it does not have any issues. You also need to find out what the gearing ratios are and whether they are going to work with your rear gear ratio. The TKO 600 is geared for the 3.70 rear gear and the TKO 500 is geared for the 3.36 and 3.08. The drive shaft is shorter and the trans end is splined different than the oem shaft. American Powertrain supplied a short adapter cable for the speedometer hookup. I did have to go to the local Ford dealer and change the gear in the trans. The speedometer was 5 mph off at 60. It is dead on now. Also, it is probably easier to pull the engine for the install vs the clamshell method that AP recommends. Feel free to PM me if you like. You also have to change the pilot shaft bushing to a new bearing that fits the TKO. The shaft alignment has to be checked and corrected if necessary.

MarkC

The frame does not need to be cut for the install. My was not cut. But, it sure makes it easier to install with a removable crossmember. There was a tread several weeks ago on making the crossmember removable.

856666

Sam,

I installed the RS400 (T45) in my L79 myself after having similar problems as you with my Muncie and the desire to highway drive under 3500 RPM.

The install was straight forward with no modification of the cross member and the Perfect Fit has everything you need (so long as they have it in stock). I had a 3:36 but have since replaced it with a 3:55 that perc'd up my daily drives to work. As for the highway at 70 MPH it's at 2000 RPM.

Also - the RS400 is quite a bit stiffer shifting that the old Muncie.

I would do it again.

alexandervdr

I have bought the RS400 for my 327/300 in a 64, but still months out of installing it (now doing body work). I keep on hesitating between a 3:55 and the 3.36 rear end. You did both. What is the difference in driving experience?

856666

Good Question.

In my opinion the 3:55 fits the power curve of the L79 w/T45 better than the 3:36. With the 3:55 its torque'er without much difference in highway RPM - see attachment - it pulls really good 1-4 and still cruise's at 2000 rpm @ 68 mph in 5th with passing torque. The 3:36 didn't do this/or not as well.

I should explain the chart
Shows MPH in the Y and RPM (1000-2500) for each gear in the X
65M20 = Stock Muncie with 3:36
RS400 = RS400 and 336
355/RS = 355 and RS

What you see is the green RS line is a little below the blue RS line that fits the torque curve of the L79

I don't know the torque curve of the 300 HP vs 350 HP but if they are close I would go 3:55

I hope this helps.

Phil

alexandervdr

It surely does, thanks!
I have made a spreadsheet&graphs too comparing Muncie & reared rpm/speed with RS400 & rearend/speed. (or any other gearbox). I made a best guess torque curve of the standard 327/300hp (could not find any on line) and given my low rpm style driving, it confirms that a 3.55 is probably the better choice, except for first gear that does not bring me very far (but that is not a surprise because I knew very well that this is typical RS400)