Manual to automatic in a C3
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Joined: Jan 2010
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From: Quebec
Manual to automatic in a C3
Hi,
im hunting for a solid car to put a 550+hp 406 sbc and built my dream street corvette.
I was looking for an automatic car but i found a deal on a 4 speed 71 with no match 350 engine in it.
My plan would be to put a th350 in the car but i dont want to cut/weld/alter the structure of the car.
Is it a simple modification? what the parts i could need (do i need to change the pedal box or only the pedal itself) what about the console?.
im hunting for a solid car to put a 550+hp 406 sbc and built my dream street corvette.
I was looking for an automatic car but i found a deal on a 4 speed 71 with no match 350 engine in it.
My plan would be to put a th350 in the car but i dont want to cut/weld/alter the structure of the car.
Is it a simple modification? what the parts i could need (do i need to change the pedal box or only the pedal itself) what about the console?.
Racer
Joined: Jul 2009
Posts: 338
Likes: 9
From: South Bend IN
NCM Sinkhole Donor
Hi,
im hunting for a solid car to put a 550+hp 406 sbc and built my dream street corvette.
I was looking for an automatic car but i found a deal on a 4 speed 71 with no match 350 engine in it.
My plan would be to put a th350 in the car but i dont want to cut/weld/alter the structure of the car.
Is it a simple modification? what the parts i could need (do i need to change the pedal box or only the pedal itself) what about the console?.
im hunting for a solid car to put a 550+hp 406 sbc and built my dream street corvette.
I was looking for an automatic car but i found a deal on a 4 speed 71 with no match 350 engine in it.
My plan would be to put a th350 in the car but i dont want to cut/weld/alter the structure of the car.
Is it a simple modification? what the parts i could need (do i need to change the pedal box or only the pedal itself) what about the console?.
Thread Starter
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Joined: Jan 2010
Posts: 84
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From: Quebec
If the 4 speed is tough enought i would like to keep it. People around here tell me i will destroy the transmission and rear really quick. Next thing to worry about will be the rear end.
Race Director
Joined: Aug 2004
Posts: 10,628
Likes: 132
From: Duvall, WA
I'm biased (I don't think an automatic has any place in a sports car), but a Muncie should be able to hold up to the kind of power you are talking about. I had that power in my '77 Trans Am, and the Muncie held up for the 5 years I had the car. My clutches didn't last long, but the 4-speed did fine.
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Thread Starter
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Joined: Jan 2010
Posts: 84
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From: Quebec
Race Director
Joined: Apr 1999
Posts: 11,520
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From: CORVETTE 77 385 C.I. TEXAS
The LT-1 / BB hood gives minimal clearance w/ factory 2" drop base filter & LT-1 intake.
The 73-79 med. rise hood has great clearance for perf. & 1" drop base filter works w/ RPMs, Victor Jr. & others.
The 73-79 med. rise hood has great clearance for perf. & 1" drop base filter works w/ RPMs, Victor Jr. & others.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
If you simply must have an auto, buy one that came with an auto with removable x-member (and save a sportscar). FWIW, with that much power you'll need to budget a fair amount of $$$ for beefing up the rearend, especially if you go manual and/or intend on any slicks.
Last edited by TheSkunkWorks; Oct 4, 2011 at 06:06 PM.
Thread Starter
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Joined: Jan 2010
Posts: 84
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From: Quebec
I was mostly looking to put an automatic for quicker shift at the drag strip and to help the rear a bit. I dont live near a track so i wont put sticky tire too often.
On the street i would love the manual. I was planing to put some hoosier quick time dot on the street.
My mechanic told me today he can easily put the automatic transmission without doing a mess under the car. He even told me he can put it without removing the welded x-member. Is he right or full of s...?
If i keep all the 4 speed part it could be easy to put it back to 4 speed.
Im still shopping, i found another 71 automatic but 6k $ more and its a number matching car. Also not really to modify.. The problem is that here in canada we dont have as much choice than you guys have!!
On the street i would love the manual. I was planing to put some hoosier quick time dot on the street.
My mechanic told me today he can easily put the automatic transmission without doing a mess under the car. He even told me he can put it without removing the welded x-member. Is he right or full of s...?
If i keep all the 4 speed part it could be easy to put it back to 4 speed.
Im still shopping, i found another 71 automatic but 6k $ more and its a number matching car. Also not really to modify.. The problem is that here in canada we dont have as much choice than you guys have!!
Drifting
Joined: May 2007
Posts: 1,491
Likes: 2
From: North Royaton Ohio
If you MUST put an automatic in, do NOT do a Th350. No overdrive sucks. Ask my how I know. If you're going to do that, put in a 700R4 to get the deeper first gear and an overdrive.
As for hood clearance, have you considered an L88 hood? It's the best looking hood for C3's anyway (I'm kinda biased on that)
As for hood clearance, have you considered an L88 hood? It's the best looking hood for C3's anyway (I'm kinda biased on that)
Racer
Joined: Mar 2010
Posts: 378
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From: NW sub of chicago IL
two things first if you convert over pm me if you want to sell the peddle assembly and other manual parts.
second I have a 76 t-top th350 I am tearing apart to get ready for my sister. something is wrong with the ignition harness. solid frame but has surface rust paint is crap. needs new floor pans and exhaust but does come with new carpet. as far as I can tell 95 percent original. 2k IL
second I have a 76 t-top th350 I am tearing apart to get ready for my sister. something is wrong with the ignition harness. solid frame but has surface rust paint is crap. needs new floor pans and exhaust but does come with new carpet. as far as I can tell 95 percent original. 2k IL
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
I say GET IT!! And convert it to auto... If you want any real performance, you need an auto... All stick cars do is break $hit constantly and turn in crappy numbers at the drag strip. If you want to be able to show the HP your engine makes, you need an auto, good custom built converter and some moderate driveline upgrades...
You can cut out the 4spd crossmember, get a tubular crossmember from Bowtie overdrives for a 200r4 or t400(same one), drill/tap the frame and bolt it in and go...this will give you more room for the 3" exhaust you'll need without trying to cram it in those frame holes...
Build what you want, don't listen to the 4spd hype....they're slow at the strip and break all the time.
600hp with an auto = high 10s and reliable
600hp with a stick = mid to high 11s and breaking all the time..
Trust me on this....autos rule at the strip and on the roll/freeway racing.... I have been killing cars on the street because the auto always goes into the gear it needs to and always upshifts right..
That being said, I have a 6spd Z06 that I just broke the tranny in and it's costing me $3k to fix it..... If it breaks again, it's getting an auto...
You can cut out the 4spd crossmember, get a tubular crossmember from Bowtie overdrives for a 200r4 or t400(same one), drill/tap the frame and bolt it in and go...this will give you more room for the 3" exhaust you'll need without trying to cram it in those frame holes...
Build what you want, don't listen to the 4spd hype....they're slow at the strip and break all the time.
600hp with an auto = high 10s and reliable
600hp with a stick = mid to high 11s and breaking all the time..
Trust me on this....autos rule at the strip and on the roll/freeway racing.... I have been killing cars on the street because the auto always goes into the gear it needs to and always upshifts right..
That being said, I have a 6spd Z06 that I just broke the tranny in and it's costing me $3k to fix it..... If it breaks again, it's getting an auto...
Thread Starter
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Joined: Jan 2010
Posts: 84
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From: Quebec
Well, the 4 speed guys will be happy, i wont buy the car.
It was an original lt-1 with nom. The car looked nice in picture but in fact it was junk.
All the windshield frame was rusted, NO brake at all, engine bay was a mess, interior was trashed, bumper were welded (?)...
All i can say is never buy a car just by seeing pic!
I will look at another 71 today, its a # match 350 / 270 hp automatic. I hope i will have more luck with that one!
It was an original lt-1 with nom. The car looked nice in picture but in fact it was junk.
All the windshield frame was rusted, NO brake at all, engine bay was a mess, interior was trashed, bumper were welded (?)...
All i can say is never buy a car just by seeing pic!
I will look at another 71 today, its a # match 350 / 270 hp automatic. I hope i will have more luck with that one!
