Converting from smallblock to big block
Thread Starter
Instructor
Joined: Jul 2006
Posts: 150
Likes: 0
From: Cherry Point NC
Originally Posted by Durango_boy
Say he finds a small block car with an auto, and the 350 is shot. It'd be several thousand cheaper than a big block manual rigth? That's a huge difference when the drivetrain is gonna be changed anyway. Drop in a big block, a 5 spd, and some pedals and loankages and you have the car that was sought after fromt eh beginning, saving a few thousand along the way...and you have a moveable cross member. 
cars equipped with auto trans had a moveable crossmember, where the manual cars had welded in crossmembers?
Why is it soo hard to deal with a welded in xmember? I think it would be easier to do that than it would be to install a 3rd pedal, linkages, etc...
You guys know best, so tell me the best route. I planned on using the 350's tranny until we really needed a T-10.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by Malice 1
So, lemme get this straight....
cars equipped with auto trans had a moveable crossmember, where the manual cars had welded in crossmembers?
cars equipped with auto trans had a moveable crossmember, where the manual cars had welded in crossmembers?
Well, Batman will tell you best about the conversion since he's doing it to his auto '77. The car is already set up for the pedals, you just have to install them.
As far as the cross member, a bolted in unit gives you the freedom and option to move it based on what trans you use. A welded cross member would work just fine until you had to move it, and then you;re stuck with trying to cut it, move it, and re-weld it.
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
Originally Posted by Malice 1
So, lemme get this straight....
cars equipped with auto trans had a moveable crossmember, where the manual cars had welded in crossmembers?
Why is it soo hard to deal with a welded in xmember? I think it would be easier to do that than it would be to install a 3rd pedal, linkages, etc...
You guys know best, so tell me the best route. I planned on using the 350's tranny until we really needed a T-10.
cars equipped with auto trans had a moveable crossmember, where the manual cars had welded in crossmembers?
Why is it soo hard to deal with a welded in xmember? I think it would be easier to do that than it would be to install a 3rd pedal, linkages, etc...
You guys know best, so tell me the best route. I planned on using the 350's tranny until we really needed a T-10.
Muncies can be just as strong as T-10s. Some later C3s actually used ST-10s for four speed manuals. Most people doing conversions are going with 5 or 6 speed transmissions to get overdrive.
Everything I've read says that the welded crossmember is a major pain when it comes to doing things like changing the clutch.
It's all a matter of what you want to do with the car. I'd recommend searching old posts thoroughly before making a decision. Most C3 issues have been hashed out pretty well over the years. The archives can be accessed through "advanced search."
HOOK-EM HORNS
Joined: Aug 2006
Posts: 3,517
Likes: 842
From: Port Aransas, Texas Tx
St. Jude Donor '08
I really wish I had a removable cross member in my stantard. We installed the tremec witht he engine out but when I have to replace the clutch I am going to have to remove my headers, side pipes, all the necessary stuff to remove the engine, like radiator etc. I am going to have to pull my engine up and move it forward to get the trans out. Or cut and re-weld the cross member. I went with hyro clutch and if I had started with a automatic car it would have been way easier. Only about an hour or less to change out the peddles.
I am sure the engineers who designed our C-3's never thought we would be putting in things like 502's, 5 and 6 speeds, etc.
I am sure the engineers who designed our C-3's never thought we would be putting in things like 502's, 5 and 6 speeds, etc.
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Originally Posted by Vette-73
if you want a big block then buy one and enjoy the ride. Later
Yep, Buy an original big block NOM and get toasted by every new performance car on the road.
Last edited by GDaina; Oct 22, 2006 at 07:57 PM.
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Intermediate
Joined: May 2006
Posts: 49
Likes: 0
Originally Posted by turtlevette
I hate chrome bumper/big block snobs.
Yep, Buy an original big block NOM and get toasted by every new performance car on the road.
Yep, Buy an original big block NOM and get toasted by every new performance car on the road.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by Vette-73
if you want a big block then buy one and enjoy the ride. Later
No profile? I'm guessing you have a '73. What is it you have against motor swaps?
Last edited by GDaina; Oct 22, 2006 at 07:58 PM.
HOOK-EM HORNS
Joined: Aug 2006
Posts: 3,517
Likes: 842
From: Port Aransas, Texas Tx
St. Jude Donor '08
Originally Posted by turtlevette
I hate chrome bumper/big block snobs.
Yep, Buy an original big block NOM and get toasted by every new performance car on the road.
Yep, Buy an original big block NOM and get toasted by every new performance car on the road.
Senior Member since 1492
Joined: Aug 2000
Posts: 87,936
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Originally Posted by Durango_boy
No profile? I'm guessing you have a '73. What is it you have against motor swaps?
My Troll detector just went off.
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Originally Posted by TEXASRANGER
We just don't keep them stock........we change out to 502's etc. I whooped my friends 04 C5 this weekend...no contest. Can I whoop a new Z06, I don't think so, but it an't no small block. If I go to slick's etc, I might whoop him though.
So just start with a beater small block automatic car and drop the 502/572 and 6 speed in.
I would consider the new Z06 a small block. Ain't it the same LS-2 block just stroked?
That's gonna be the next hot swap cause you don't have to put that enormously high hood to make it fit. A true sleeper.
Thread Starter
Instructor
Joined: Jul 2006
Posts: 150
Likes: 0
From: Cherry Point NC
I've never been underneath one of these cars before, but since I want to stay manual, I don't forsee the solid xmember being a huge problem for me. Please remember that this car is not for me. My buddy has no desire for a T5 or T56. He also has no desire for an LS1, or a killer smallblock.
Again, does anyone know off hand if there is a kit out there which has brackets and misc. parts for this swap? The link earlier in the thread had some great info, I just want to be able to find parts easier.
Vette-73, thank you for your technical expertise.
Would you please delete your posts?
Again, does anyone know off hand if there is a kit out there which has brackets and misc. parts for this swap? The link earlier in the thread had some great info, I just want to be able to find parts easier.
Vette-73, thank you for your technical expertise.
Would you please delete your posts?
Senior Member since 1492
Joined: Aug 2000
Posts: 87,936
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Originally Posted by Malice 1
I've never been underneath one of these cars before, but since I want to stay manual, I don't forsee the solid xmember being a huge problem for me. Please remember that this car is not for me. My buddy has no desire for a T5 or T56. He also has no desire for an LS1, or a killer smallblock.
Again, does anyone know off hand if there is a kit out there which has brackets and misc. parts for this swap? The link earlier in the thread had some great info, I just want to be able to find parts easier.
Vette-73, thank you for your technical expertise. Would you please delete your posts?
Again, does anyone know off hand if there is a kit out there which has brackets and misc. parts for this swap? The link earlier in the thread had some great info, I just want to be able to find parts easier.
Vette-73, thank you for your technical expertise.
Would you please delete your posts?
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Originally Posted by TEXASRANGER
Need the low mount engine mounts. Will have to modify the exhaust. Hood clearance might be a problem. PLENTY COOLING. If using a HEI it will hit your windshiled wiper motor and you will have to route your wires according. Need heavy duty half shafts, non greasable for strength.
Modify the exhaust? I bought a set of cheap Heddman headers and they fell right into place. Good fit and lasted me 15 years.
I did also use the 350 distributor, the front coil springs and the stock rad for a number of years before upgrading.
I used 280 pound springs for almost 20 years with various bigblocks and loved them.
the 75 comes with the larger half shafts but again I used greasable u joints and never had a failure in 20 years and that included my nitrous motor, slicks and my present blower motor.
The swap is very simple and alot of the smallblock parts work for the bigblock.
good luck
Forgot hood clearance. I used the high rise LS6 intake and had to clean up the underside of the stock hood and run a drop base air cleaner and a 2 inch element.