Resto Mod questions
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Joined: Apr 2008
Posts: 54
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From: Memphis TN
Resto Mod questions
1. I purchased a 66 with a 3.71 rear gear and stock 4 speed transmission. I would like to bring the rpms down in 4th on the hwy and cruise at about 70mph on weekend trips (approx 300 miles) Will I get anything out of changing the rear gear to 3.55 or should I be thinking more along the lines of a new transmission like tremec 500 or 600?
2. Has anyone purchased/installed the drilled and slotted rotors seen on several of the ebay auctions? They seem reasonably priced but I don't want to burned and waste time and money on crappy products.
Thanks,
Bee
2. Has anyone purchased/installed the drilled and slotted rotors seen on several of the ebay auctions? They seem reasonably priced but I don't want to burned and waste time and money on crappy products.
Thanks,
Bee
Team Owner
Joined: Aug 2007
Posts: 58,061
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Army
1. I purchased a 66 with a 3.71 rear gear and stock 4 speed transmission. I would like to bring the rpms down in 4th on the hwy and cruise at about 70mph on weekend trips (approx 300 miles) Will I get anything out of changing the rear gear to 3.55 or should I be thinking more along the lines of a new transmission like tremec 500 or 600?
Bee
Bee
Race Director
Joined: Jun 2006
Posts: 17,901
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From: Inverness FL
St. Jude Donor '07
going to a 3.55 will only save a couple hundred RPMs. a 4spd overdrive trans like the MY-6 is an easy swap; or get a 5spd.
Bill
Bill
Last edited by wmf62; Mar 2, 2009 at 07:14 PM.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
1. I purchased a 66 with a 3.71 rear gear and stock 4 speed transmission. I would like to bring the rpms down in 4th on the hwy and cruise at about 70mph on weekend trips (approx 300 miles) Will I get anything out of changing the rear gear to 3.55 or should I be thinking more along the lines of a new transmission like tremec 500 or 600?
2. Has anyone purchased/installed the drilled and slotted rotors seen on several of the ebay auctions? They seem reasonably priced but I don't want to burned and waste time and money on crappy products.
Thanks,
Bee
2. Has anyone purchased/installed the drilled and slotted rotors seen on several of the ebay auctions? They seem reasonably priced but I don't want to burned and waste time and money on crappy products.
Thanks,
Bee
Race Director
Joined: Jun 2006
Posts: 17,901
Likes: 751
From: Inverness FL
St. Jude Donor '07
try these threads
http://forums.corvetteforum.com/c1-a...sion-swap.html
http://forums.corvetteforum.com/c1-a...-4th-gear.html
http://forums.corvetteforum.com/c1-a...ed-muncie.html
http://forums.corvetteforum.com/c1-a...overdrive.html
they pop up once in a while; there was one that sold for a total of $375 on ebay last week. i also think the OD conversion gears for a muncie would be a viable option.
Bill
http://forums.corvetteforum.com/c1-a...sion-swap.html
http://forums.corvetteforum.com/c1-a...-4th-gear.html
http://forums.corvetteforum.com/c1-a...ed-muncie.html
http://forums.corvetteforum.com/c1-a...overdrive.html
they pop up once in a while; there was one that sold for a total of $375 on ebay last week. i also think the OD conversion gears for a muncie would be a viable option.
Bill
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Drifting
Joined: Oct 1999
Posts: 1,276
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From: whitney pt. N.Y., USA ny
I've been looking at a different approach. I purchased a Doug Nash (Richmond Gear Tranny) 5 speed with a 3.27 low as opposed to the 2.52 low of a Muncie 4 speed with a 3:08 rear gear set. 1st gear should be friendly and aggressive. 3:08 in fifth should be a good highway gear. I can't do the work myself anymore and probably will never drive it but It should be a great car to leave to my sons. The 383 with aluminum heads is already in the 67 and is a great power plant so with this set up added it should be a great Corvette.
Le Mans Master
Joined: Jan 2005
Posts: 8,226
Likes: 2
From: Lake Wylie SC
I agree with the comments posted regarding the advantages of a 5 speed so I would like to move on to your second question regarding the brakes.
If you need new rotors the stock replacements will do everything that the fancy slotted and drilled ones will do with the only significant difference being that the stock ones will do it for considerable less money.
However where you can make a drastic improvement is in the calipers and switch to the new Wildwoods. They are far lighter and everything that was bad about the original brakes is corrected with them. They have made the hydroboost upgrade to be a waste of money and will bring a C2 into a class of performance never available before.
Doug
If you need new rotors the stock replacements will do everything that the fancy slotted and drilled ones will do with the only significant difference being that the stock ones will do it for considerable less money.
However where you can make a drastic improvement is in the calipers and switch to the new Wildwoods. They are far lighter and everything that was bad about the original brakes is corrected with them. They have made the hydroboost upgrade to be a waste of money and will bring a C2 into a class of performance never available before.
Doug
Race Director
Joined: Jun 2006
Posts: 17,901
Likes: 751
From: Inverness FL
St. Jude Donor '07
I've been looking at a different approach. I purchased a Doug Nash (Richmond Gear Tranny) 5 speed with a 3.27 low as opposed to the 2.52 low of a Muncie 4 speed with a 3:08 rear gear set. 1st gear should be friendly and aggressive. 3:08 in fifth should be a good highway gear. I can't do the work myself anymore and probably will never drive it but It should be a great car to leave to my sons. The 383 with aluminum heads is already in the 67 and is a great power plant so with this set up added it should be a great Corvette.
, that is a good approach if you already have a 3.08. the MY-6 has a 3.09 1st gear and a .73 4th which allows it to carry my 3.36 and effectively changes it to a 2.45 at cruise.that is the beauty of an OD trans
Bill
Melting Slicks
Joined: Oct 2004
Posts: 3,345
Likes: 87
From: Northern MN
St. Jude Donor '13-'14-'15-'16-'17
try these threads
http://forums.corvetteforum.com/c1-a...sion-swap.html
http://forums.corvetteforum.com/c1-a...-4th-gear.html
http://forums.corvetteforum.com/c1-a...ed-muncie.html
http://forums.corvetteforum.com/c1-a...overdrive.html
they pop up once in a while; there was one that sold for a total of $375 on ebay last week. i also think the OD conversion gears for a muncie would be a viable option.
Bill
http://forums.corvetteforum.com/c1-a...sion-swap.html
http://forums.corvetteforum.com/c1-a...-4th-gear.html
http://forums.corvetteforum.com/c1-a...ed-muncie.html
http://forums.corvetteforum.com/c1-a...overdrive.html
they pop up once in a while; there was one that sold for a total of $375 on ebay last week. i also think the OD conversion gears for a muncie would be a viable option.
Bill
Bill,
I have a some of questions.
First: Do you have to change the tail shaft and rear housing on the MY 6 to get it to fit the existing drive shaft, etc.? All photos of this unit appear to have the long tail shaft.
Secondly: If a person was to go looking for one is there any distinquishing numbers or markings on the case that tells you if it is a GM unit and not a Mopar setup?
Third: Are these cases Aluminum or Cast Iron? They appear to be Cast Iron in all the literature I found.
Fourth: Do the GM units from 81 to 86 bolt up to the older bell housings? I assume that the newer versions do, am I correct here?
I wouldn't mind going this route on my car if feasible. I have 3:70 rear gears and turn approximately 2800 rpm (it maybe more) at 60 mph.
Thanks for any help.
Steve
Race Director
Joined: Jun 2006
Posts: 17,901
Likes: 751
From: Inverness FL
St. Jude Donor '07
Bill,
I have a some of questions.
First: Do you have to change the tail shaft and rear housing on the MY 6 to get it to fit the existing drive shaft, etc.? All photos of this unit appear to have the long tail shaft.
Secondly: If a person was to go looking for one is there any distinquishing numbers or markings on the case that tells you if it is a GM unit and not a Mopar setup?
Third: Are these cases Aluminum or Cast Iron? They appear to be Cast Iron in all the literature I found.
Fourth: Do the GM units from 81 to 86 bolt up to the older bell housings? I assume that the newer versions do, am I correct here?
I wouldn't mind going this route on my car if feasible. I have 3:70 rear gears and turn approximately 2800 rpm (it maybe more) at 60 mph.
Thanks for any help.
Steve
I have a some of questions.
First: Do you have to change the tail shaft and rear housing on the MY 6 to get it to fit the existing drive shaft, etc.? All photos of this unit appear to have the long tail shaft.
Secondly: If a person was to go looking for one is there any distinquishing numbers or markings on the case that tells you if it is a GM unit and not a Mopar setup?
Third: Are these cases Aluminum or Cast Iron? They appear to be Cast Iron in all the literature I found.
Fourth: Do the GM units from 81 to 86 bolt up to the older bell housings? I assume that the newer versions do, am I correct here?
I wouldn't mind going this route on my car if feasible. I have 3:70 rear gears and turn approximately 2800 rpm (it maybe more) at 60 mph.
Thanks for any help.
Steve
the MY-6 is a special version of the Chrysler 833 that was made specifically for GM for use in vans and pickups. to the best of my knowledge all the MY-6s are all aluminum and have a short tailshaft housing (if it's a cast iron case and with a long housing, its a Chrysler trans); it is an exact replacement for the Muncie, EXCEPT that it has to use the bellhousing with the large bearing retainer hole. if you use a fully enclosed aluminum bellhousing then an adapter will have to be made for the Zbar to mount to on the engine end, but if you use a cast iron open bottomed truck bellhousing then the old parts can be used. REMEMBER, the bellhousing MUST have the LARGE bearing retainer hole, not the Muncie sized hole.
we used my regular Hurst Competition Plus shifter but had to make an adapter plate to mount it to the tailshaft housing and modified the shifter rods to fit.
Bill
Melting Slicks
Joined: Oct 2004
Posts: 3,345
Likes: 87
From: Northern MN
St. Jude Donor '13-'14-'15-'16-'17
Steve
the MY-6 is a special version of the Chrysler 833 that was made specifically for GM for use in vans and pickups. to the best of my knowledge all the MY-6s are all aluminum and have a short tailshaft housing (if it's a cast iron case and with a long housing, its a Chrysler trans); it is an exact replacement for the Muncie, EXCEPT that it has to use the bellhousing with the large bearing retainer hole. if you use a fully enclosed aluminum bellhousing then an adapter will have to be made for the Zbar to mount to on the engine end, but if you use a cast iron open bottomed truck bellhousing then the old parts can be used. REMEMBER, the bellhousing MUST have the LARGE bearing retainer hole, not the Muncie sized hole.
we used my regular Hurst Competition Plus shifter but had to make an adapter plate to mount it to the tailshaft housing and modified the shifter rods to fit.
Bill
the MY-6 is a special version of the Chrysler 833 that was made specifically for GM for use in vans and pickups. to the best of my knowledge all the MY-6s are all aluminum and have a short tailshaft housing (if it's a cast iron case and with a long housing, its a Chrysler trans); it is an exact replacement for the Muncie, EXCEPT that it has to use the bellhousing with the large bearing retainer hole. if you use a fully enclosed aluminum bellhousing then an adapter will have to be made for the Zbar to mount to on the engine end, but if you use a cast iron open bottomed truck bellhousing then the old parts can be used. REMEMBER, the bellhousing MUST have the LARGE bearing retainer hole, not the Muncie sized hole.
we used my regular Hurst Competition Plus shifter but had to make an adapter plate to mount it to the tailshaft housing and modified the shifter rods to fit.
Bill
Thanks for the information. Wasn't sure of anything just by reading the previous posts. I'll do some checking locally to see what I can find.
Did any of the Late 50 to 60 Bellhousings use the larger diameter bearing retainer that were aluminum different from the one you used? What bellhousing did you use?
Steve
Race Director
Joined: Jun 2006
Posts: 17,901
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From: Inverness FL
St. Jude Donor '07
There are actually TWO of this version of transmission available for Chevy applications: One has a Mopar mounting pattern, and needs to be used with the aluminum bellhousing it came with originally.
The other version of this trans has the case retooled to have a Chevy trans bolt pattern, allowing it to bolt to a regular Chevy bellhousing...with a larger pilot hole (approx 5-1/8" diameter for the MY-6 large hole, approx 4-7/8" for the Muncie hole). I have one of these,(see the pix of the aluminum bellhousing, especially the one from the rear). the spacing between the edge of the thowout fork pivot and the edge of the hole is the visual thing to look for when looking for a 'big hole' bellhousing.
The cast iron Chevy truck bellhousing has a rear mount pad on each side of the bellhousing (look at the pic of the orange bellhousing). again, look for the spacing between the pivot bolt and the hole, then measure...
Chevy made an aluminum open bottom bellhousing for the Corvette similar to the truck bellhousing, but i'm reasonably sure that it does not have the LARGE hole needed for the MY-6.
Bill
Melting Slicks
Joined: Oct 2004
Posts: 3,345
Likes: 87
From: Northern MN
St. Jude Donor '13-'14-'15-'16-'17
There are actually TWO of this version of transmission available for Chevy applications: One has a Mopar mounting pattern, and needs to be used with the aluminum bellhousing it came with originally.
The other version of this trans has the case retooled to have a Chevy trans bolt pattern, allowing it to bolt to a regular Chevy bellhousing...with a larger pilot hole (approx 5-1/8" diameter for the MY-6 large hole, approx 4-7/8" for the Muncie hole). I have one of these,(see the pix of the aluminum bellhousing, especially the one from the rear). the spacing between the edge of the thowout fork pivot and the edge of the hole is the visual thing to look for when looking for a 'big hole' bellhousing.
The cast iron Chevy truck bellhousing has a rear mount pad on each side of the bellhousing (look at the pic of the orange bellhousing). again, look for the spacing between the pivot bolt and the hole, then measure...
Chevy made an aluminum open bottom bellhousing for the Corvette similar to the truck bellhousing, but i'm reasonably sure that it does not have the LARGE hole needed for the MY-6.
Bill
Dumb question. How about having an aluminum bellhousing opened up to the 5 1/8" diameter? There are plenty of old aluminum bellhousing around that take the standard 11" clutch. Would that be a way to go?
Steve
Race Director
Joined: Jun 2006
Posts: 17,901
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From: Inverness FL
St. Jude Donor '07
good question...
maybe... you'd have to look at the inside of the bellhousing, around the present hole. to see if it is thick enough or reinforced right so that when the hole is opened up it is still sufficiently reinforced.
Bill
maybe... you'd have to look at the inside of the bellhousing, around the present hole. to see if it is thick enough or reinforced right so that when the hole is opened up it is still sufficiently reinforced.
Bill
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Joined: Apr 2008
Posts: 54
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From: Memphis TN
Thanks WMF62 and SHURSHOT for the addition information. Looks like I have some homework to do. BTW, at some point a 1971 350 (I think) was placed in my 66 (Non-numbers car). I'm guessing the hp is around 350-400 due to engine mods. I'm not sure what the torque is but I need to be sure the MY-6 can hold up to the specs. I don't plan on racing the car but I would like to have the piece of mind in knowing I can get on it without breaking something.
b
b
Race Director
Joined: Jun 2006
Posts: 17,901
Likes: 751
From: Inverness FL
St. Jude Donor '07
Thanks WMF62 and SHURSHOT for the addition information. Looks like I have some homework to do. BTW, at some point a 1971 350 (I think) was placed in my 66 (Non-numbers car). I'm guessing the hp is around 350-400 due to engine mods. I'm not sure what the torque is but I need to be sure the MY-6 can hold up to the specs. I don't plan on racing the car but I would like to have the piece of mind in knowing I can get on it without breaking something.
b
b
Bill
Melting Slicks
Joined: Oct 2004
Posts: 3,345
Likes: 87
From: Northern MN
St. Jude Donor '13-'14-'15-'16-'17
Bill,
Did you happen to photo the MY-6 you installed and can you post it? The old Chrysler A833 had a longer tail shaft on it, did it not? It is the main housing and gears that are the same or am I totally under water on this?
Steve