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View Full Version : 406 vs 383?



Rybar
10-29-2004, 10:02 AM
Hey guys, I know I'm still far away from getting the motor for my '69 but I wanted ask some opinions.

I originally wanted to go with a 383 and wanted to make 450-500 hp N/A, I don't want any power adders, had them before on my '94 LT1 TA and don't want the hassles. I want reliable HP but I also want good lowend torque and for the motor to make power up to 6000-6500 rpm.

Now I'm contemplating a 406 SB.

What do you guys think? Should I just stick to my original goals or move to the 406?

I'm kind of on a tight budget, so I don't really have the $$$ to go all out like alot of the guys on the site.

justanova
10-29-2004, 03:07 PM
If you have access to a 400 block I would say go 406, It shouldn't be much more expensive to build than a 383, but a 383 should also meet your goals with no problems.

TurboLark
10-29-2004, 05:06 PM
The only problem i have with the 400 is the block. They came in heavy vehicles and got worked hard from day one. I was to build one for my 4x4. i went thru 6, yes 6, 400 blocks before i gave up and went to a 383. the main decks cracked all to hell when the torqueplate was put on. For your sanity, build a 383 or build the 406 with an aftermarket block.

gmachinz
10-31-2004, 08:28 PM
My experience with 400's have been good. My friend (SonicBlue70) has a '70 Camaro that ran 7.69 in the 1/8 mile before we realized the previous owner put 350 heads on it without drilling for the steamholes- :scared: So after going .030-over with a fresh block and me doing the porting on the heads, upgrading the fuel system and dropping some weight we should be in the low- 7's on just motor-great considering it's a production block and a stock crank. Then for a heavy car, I have another friend who had a '70 Monte with the factory four-bolt 400 and it was built .030-over and he never had any problems with it at all. I have no numbers on it-but it really launched that 4400lb. boat I 'll tell you that! Pay the extra money to have the 400 block magnafluxed and sonic-checked to find out if there are any "spider" cracks which will lead to big problems once some torque is applied. They are great motors but yes, most are pulled from trucks which were used/abused and put away wet. Here in the midwest they are fairly easy to find still with so many old ex-farm and snowplow pick-ups sitting around rotting away. Not the greatest of options but hey, unless you can shell out big bucks for aftermarket blocks for every engine build, what options are you left with? -Jabin