2 bolt/4 bolt/400 trans ?
Thread Starter
Le Mans Master
Joined: Nov 2004
Posts: 7,186
Likes: 45
From: detroit area
2 bolt/4 bolt/400 trans ?
i came across a 350 2 bolt main and a 350 4 bolt main.....is the 4 bolt better?
and a 400 trans...... is that an automatic?..... might pick up these items for my dads poject car....
b
and a 400 trans...... is that an automatic?..... might pick up these items for my dads poject car....
b
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
the 4 bolt as its name implies has 4 bolts in the main bearing carriers in the bottom of the motor, it is a stronger bottom than the 2 bolt is so its a better choice if you have choices. The 400 is an auto trans, actually its a GM Turbo Hydromatic 350. I think the 350 part indicated the HP rating on the transmissions
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
For a street type engine it makes little difference 2 bolt or 4 bolt mains. If you can buy them for the same price I'd probably buy the 4 bolt, but I'd rather have less bore than a 4 bolt block.
A 400 transmission is a TH400. It is the stronger of the 2 GM mainstay automatic transmissions available in the C3. The other main automatic was the TH350. Later C3s had a TH350 with lockup torque converter. The lockup portion is not very strong in these. All 82 Corvettes had a 700R4 overdrive automatic, that was the first year for it in any GM cars. For a street car without overdrive, a non-lockup TH350 is a good trans. For a higher pefrormance street car without overdrive, a TH400 is a stronger trans. If you want max drag strip performance, a TH350 is faster and lighter and takes less power to run, however it is less relaible long term in max race tune. A TH400 is a very strong, reliable trans.
In either case, it depends on what you are looking for.
A 400 transmission is a TH400. It is the stronger of the 2 GM mainstay automatic transmissions available in the C3. The other main automatic was the TH350. Later C3s had a TH350 with lockup torque converter. The lockup portion is not very strong in these. All 82 Corvettes had a 700R4 overdrive automatic, that was the first year for it in any GM cars. For a street car without overdrive, a non-lockup TH350 is a good trans. For a higher pefrormance street car without overdrive, a TH400 is a stronger trans. If you want max drag strip performance, a TH350 is faster and lighter and takes less power to run, however it is less relaible long term in max race tune. A TH400 is a very strong, reliable trans.
In either case, it depends on what you are looking for.
Thread Starter
Le Mans Master
Joined: Nov 2004
Posts: 7,186
Likes: 45
From: detroit area
i could get the 350 4 bolt and 400 trans for around 400 bucks total..... not bad..... basically it'll be a street car with a little bit of power....... that's the idea.......
i'm gonna check it out this week probably.....
b
i'm gonna check it out this week probably.....
b
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by onaqwst
i could get the 350 4 bolt and 400 trans for around 400 bucks total..... not bad..... basically it'll be a street car with a little bit of power....... that's the idea.......
i'm gonna check it out this week probably.....
b
i'm gonna check it out this week probably.....
b
Thread Starter
Le Mans Master
Joined: Nov 2004
Posts: 7,186
Likes: 45
From: detroit area
true........ i am looking at a 76 that needs a trans/motor so i'm just trying to piece a few things together...... maybe i'll make a few calls to a few friends to see if i can locate a better deal....
b
b
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by SIXFOOTER
the 4 bolt as its name implies has 4 bolts in the main bearing carriers in the bottom of the motor, it is a stronger bottom than the 2 bolt is so its a better choice if you have choices. The 400 is an auto trans, actually its a GM Turbo Hydromatic 350. I think the 350 part indicated the HP rating on the transmissions
No the 400 is not a Turbo 350! It is a Turbo 400. The Turbo 400 name comes from the original designation years back, of how much torque the trans could handle . The Turbo 350 was only rated at that much torque, whereas the Turbo 400 could handle 400+ foot pounds of torque. They are completely different transmissions but yea they are both automagic.
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by onaqwst
i could get the 350 4 bolt and 400 trans for around 400 bucks total..... not bad..... basically it'll be a street car with a little bit of power....... that's the idea.......
i'm gonna check it out this week probably.....
b
i'm gonna check it out this week probably.....
b
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Thread Starter
Le Mans Master
Joined: Nov 2004
Posts: 7,186
Likes: 45
From: detroit area
thanks for the info..... i'm waiting on a call back..... i might just get both the 2/4bolt 350 and the trans...... this way i can build a motor for my dad with trans and possibly build me a bigger motor for my 77...hehe......
b
b
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Originally Posted by onaqwst
i came across a 350 2 bolt main and a 350 4 bolt main.....is the 4 bolt better? and a 400 trans...... is that an automatic?..... might pick up these items for my dads poject car....b
Melting Slicks
Joined: Dec 2001
Posts: 2,025
Likes: 1
From: Billings MT
I run a "509" 2-bolt 400 block with ARP main studs to 7300rpm regularly and drag race it. After 15,000 miles and 140+ passes everything looked peachy on teardown and I am now putting it back together.
Drifting
Joined: Jun 2005
Posts: 1,950
Likes: 498
From: Chino Hills CA
If you go to your local pull-it-yourself wrecking yard, you can pick up a complete engine for $180.00. If you wait til half-price day, it'll cost you $90 plus $40 core = $130. Just bring a book with block casting numbers so you'll know what you're looking for. The only thing is many small blocks use the same casting #'s for 2 and 4 bolt mains and by the time you pull the engine, you're too beat to pull the pan. There's still plenty of 350's out there, a few small block 400's and occasionally a low compression 454.(check late 70's GM trucks.) Save the rest of your dough for a T-5 which you can find for $300-400.
Thread Starter
Le Mans Master
Joined: Nov 2004
Posts: 7,186
Likes: 45
From: detroit area
i have been double thinking this also...... the last thing i want is to buy some b.s. that has bad parts/block/case/etc..... i might wait to i can get enough cash together and do it right...... the guy that did my valves/heads might have a "special" for me since he used to work with my dad back in the day at the machine shop and since it's a gift, he might help me out a bit....
b
thanks for all the input...... just more space to be filled in the brain..
b
thanks for all the input...... just more space to be filled in the brain..