Considering a cheap 406 build, thoughts?
Race Director
Joined: Apr 2003
Posts: 19,352
Likes: 654
From: Tampa, Florida
Define 'cheap'
Dart 03114002 $4628
https://www.summitracing.com/int/par...4002/overview/
Dart 03124272 $5898
https://www.summitracing.com/int/parts/drt-03124272
Dart 03114002 $4628
https://www.summitracing.com/int/par...4002/overview/
Dart 03124272 $5898
https://www.summitracing.com/int/parts/drt-03124272
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Go 406.....don't look back.
I run a flat tappet 10.5:1 406 with Dart heads.......it is much more powerful than any 383 I have ever driven. The heads love the big bore and the torque is flat as Kansas......
Mine makes about 500 horsepower......which is plenty.....
Do not worry about 2 or 4 bolt block strength at this level.....I do not have to rev more than 6000 to do the job.
I built mine carb to pan for $5000.
Jebby
I run a flat tappet 10.5:1 406 with Dart heads.......it is much more powerful than any 383 I have ever driven. The heads love the big bore and the torque is flat as Kansas......
Mine makes about 500 horsepower......which is plenty.....
Do not worry about 2 or 4 bolt block strength at this level.....I do not have to rev more than 6000 to do the job.
I built mine carb to pan for $5000.
Jebby
Last edited by Jebbysan; Sep 1, 2017 at 06:56 PM.
Melting Slicks
Joined: Mar 2008
Posts: 2,666
Likes: 289
From: Spring Park MN
A friend of mine was having some issues with the tune on his 406 in a 79 Vette a month or so ago, so I helped him out and went for a few spins in his car. I'll skip the problems, I fixed them.
The engine is a stock 2 bolt block and cast crank with 350 5.7 rods, dished pistons topped with a pair of 186 heads with 2.02" valves. The compression was 9 to 1 with a fairly lumpy hydraulic flat tappet cam that he couldn't remember the specs on. From the sound and powerband, I would guess somewhere in the 230's range at 0.050". It had a Quadrajet on a matching Performer RPM manifold and 1 5/8" headers.
It was the definition of a low budget build. It ran pretty good, revved OK, pulled better than a similarly built 350 would have. It is definitely at the other end of the spectrum from my 406, but it was way more powerful than the original 350 would have been and he was happy with it.
Mike
The engine is a stock 2 bolt block and cast crank with 350 5.7 rods, dished pistons topped with a pair of 186 heads with 2.02" valves. The compression was 9 to 1 with a fairly lumpy hydraulic flat tappet cam that he couldn't remember the specs on. From the sound and powerband, I would guess somewhere in the 230's range at 0.050". It had a Quadrajet on a matching Performer RPM manifold and 1 5/8" headers.
It was the definition of a low budget build. It ran pretty good, revved OK, pulled better than a similarly built 350 would have. It is definitely at the other end of the spectrum from my 406, but it was way more powerful than the original 350 would have been and he was happy with it.
Mike
Racer
Joined: Aug 2012
Posts: 280
Likes: 0
From: Glendon Alberta
400
Post #37 on this page... then skip to the last 2 pages to see how right he was about rod length..
https://www.corvetteforum.com/forums...-400-ci-2.html
https://www.corvetteforum.com/forums...-400-ci-2.html
Race Director
Joined: Mar 2017
Posts: 11,953
Likes: 4,508
From: Virginia
Sounds good. Can you post the component list, or point us to a build thread?
Any updates mobird?
I'm considering doing the same in my free time (ha!) this winter. The only problem is that a complete 350 short block from GM costs the same as a Dart SHP 406 bare block. No comparison once built, I know, but having never built an engine before, I'd feel pretty bad dropping $5-$6K on it only to screw up the bottom end.
Any updates mobird?
I'm considering doing the same in my free time (ha!) this winter. The only problem is that a complete 350 short block from GM costs the same as a Dart SHP 406 bare block. No comparison once built, I know, but having never built an engine before, I'd feel pretty bad dropping $5-$6K on it only to screw up the bottom end.
Last edited by Bikespace; Oct 19, 2017 at 05:41 PM.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Thread Starter
Burning Brakes
Joined: Mar 2016
Posts: 1,008
Likes: 163
Sounds good. Can you post the component list, or point us to a build thread?
Any updates mobird?
I'm considering doing the same in my free time (ha!) this winter. The only problem is that a complete 350 short block from GM costs the same as a Dart SHP 406 bare block. No comparison once built, I know, but having never built an engine before, I'd feel pretty bad dropping $5-$6K on it only to screw up the bottom end.
Any updates mobird?
I'm considering doing the same in my free time (ha!) this winter. The only problem is that a complete 350 short block from GM costs the same as a Dart SHP 406 bare block. No comparison once built, I know, but having never built an engine before, I'd feel pretty bad dropping $5-$6K on it only to screw up the bottom end.
The update is that financially this engine build will probably have to wait a few more months. Still keeping my eye on craigslist for good deals. But basically I decided I'll be getting a Dart block and building a 406 or 421. Mostly because I already have a fairly hot 350, and it would suck to dump thousands into building a 383 and then decide it wasn't as much power as I wanted.
Race Director
Joined: Mar 2017
Posts: 11,953
Likes: 4,508
From: Virginia
The update is that financially this engine build will probably have to wait a few more months. Still keeping my eye on craigslist for good deals. But basically I decided I'll be getting a Dart block and building a 406 or 421. Mostly because I already have a fairly hot 350, and it would suck to dump thousands into building a 383 and then decide it wasn't as much power as I wanted.
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