383 or 400 SB
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Pro
Joined: Jun 2001
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From: Pflugerville/ Colllege Station TX
383 or 400 SB
I need to rebuild or replace my motor and i have the opportunity to get a 400 small block cheap or i could use my block and make it into a 383. The total cost will be about the same because im basically getting the block for free. Is there any reason to choose one over the other besides displacement. It will be a street car that i take to the strip and run on the autox course. I would like to get it into the mid to low 12s on motor. :D
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From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
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Re: 383 or 400 SB (Jack Sweet)
The 400 blocks have siamised (sp?) bores, and as such have marginal cooling around the cylinder bores.
You ever wonder why you don't see 400's in production?
They had a serious cooling problem and tend to over heat easily. And, that with the fact that you are in TX, I would say dump the 400 block and go for the 383.
You ever wonder why you don't see 400's in production?
They had a serious cooling problem and tend to over heat easily. And, that with the fact that you are in TX, I would say dump the 400 block and go for the 383.
Melting Slicks
Joined: Jun 2001
Posts: 2,429
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From: CA
Re: 383 or 400 SB (Jester69Stingray)
You want to be deep in the 12's? How many times?
You'll need a strong bottom end to go that fast without commig apart. I don't think a "free" 400 will do that for you.
Build the 400 & run lots of nitrous.
You'll need a strong bottom end to go that fast without commig apart. I don't think a "free" 400 will do that for you.
Build the 400 & run lots of nitrous.
Le Mans Master
Joined: Jul 2001
Posts: 9,622
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From: absecon nj
Re: 383 or 400 SB (71coupe)
first off you cant put a 400 crank in a 350 block with out machining the mains first..smaller...in stock form...check with your machine shop first to see the price...around here its somewhere in the high 175 to 200 mark...id build the 400 personally ..i just took mine out for too high compressio but now i wish i had it back.if your gone to build the 383 you would have to get pistons still also by that time you could get a kit already done..like 79 toy said 377 would be nice too...just need bearing spacers in the 400 block for the 350 carnk.
[Modified by pats406nitrovette, 6:57 AM 11/11/2001]
[Modified by pats406nitrovette, 6:57 AM 11/11/2001]
Pro
Joined: Jun 2001
Posts: 672
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From: Quebec
Re: 383 or 400 SB (pats406nitrovette)
Hi,
Is it the 2 bolts main? The 4 bolts main is prone to crack. If so I'd built the 400, with that displacement, it would be easy to achieve your goal of performance. Simple is better. For the cooling, be sure to have a big radiator and you'll have no trouble at all. That's the engine that was on my last camaro 1978 and it was great. Lot's of torque.
Stephan
Is it the 2 bolts main? The 4 bolts main is prone to crack. If so I'd built the 400, with that displacement, it would be easy to achieve your goal of performance. Simple is better. For the cooling, be sure to have a big radiator and you'll have no trouble at all. That's the engine that was on my last camaro 1978 and it was great. Lot's of torque.
Stephan
C6 the C5 of tomorrow
Joined: Nov 2000
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From: Twin Cities Minnesota
Re: 383 or 400 SB (BSeery)
This is a complete myth.
It gets every bit as hot and humid here in Minnesota as is does in texas just not as often or for as long. I have a 434 small block which is a stroked 400 + .030 over. It runs at 190-200' all day even those high humidity 95' + days.
AND this is with the STOCK smallblock radiator, stock water pump and an automatic!
The key to cooling a 400 is the steam holes. Make sure the heads you get ( and the gasket ) have the steam holes!
It gets every bit as hot and humid here in Minnesota as is does in texas just not as often or for as long. I have a 434 small block which is a stroked 400 + .030 over. It runs at 190-200' all day even those high humidity 95' + days.
AND this is with the STOCK smallblock radiator, stock water pump and an automatic!
The key to cooling a 400 is the steam holes. Make sure the heads you get ( and the gasket ) have the steam holes!
The 400 blocks have siamised (sp?) bores, and as such have marginal cooling around the cylinder bores.
You ever wonder why you don't see 400's in production?
They had a serious cooling problem and tend to over heat easily. And, that with the fact that you are in TX, I would say dump the 400 block and go for the 383.
You ever wonder why you don't see 400's in production?
They had a serious cooling problem and tend to over heat easily. And, that with the fact that you are in TX, I would say dump the 400 block and go for the 383.
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Pro
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Re: 383 or 400 SB (427V8)
I agree with 427V8. I've built several small blocks using the 400 block and the key to keeping them cool is the steam holes in the heads & good head gaskets. In the early blocks you need to drill a 7/16" hole on each bank as well. You can buy 6" rods and shorter pistons for a little more than stock replacements. The forged pistons are a little more but worth it. Longer rod = more power = big smiles.
Drifting
Joined: Sep 2001
Posts: 1,427
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From: Boxford Mass
Re: 383 or 400 SB (Racer16k)
An old thread on 400 sbc heads that discussed the block a bit. It may be interesting to review...
http://forums.corvetteforum.com/zerothread?id=159042
http://forums.corvetteforum.com/zerothread?id=159042
