406 vs 400 sbc

L

Link

Not-quite-so-new-guy
Feb 13, 2018
24
1
3
#1
I am thinking of doing a 406 build and I was wondering if it would be better to just keep it a 400 for a budget drag build
 
lilbowtie

lilbowtie

Royal Smart Person
Jan 7, 2006
2,151
1,089
113
Canton Mi
#2
If you have a measured good std bore why would you ?
 
melloelky

melloelky

G-Body Guru
Oct 22, 2017
666
526
93
mass
#3
lilbowtie's right, if you don't have to why bother.depending on what your plans are come into play also.
 
B

bracketchev1221

Greasemonkey
Jan 18, 2018
217
129
43
#5
I would use whatever could get a clean hone with a torque plate and keep piston to wall acceptable.
 
8

88ss408

Master Mechanic
Feb 25, 2007
274
13
18
baie st anne n.b
#6
A 406 is a .030 overbore. If your standard bore is good run with it. But if you have to bore and can get away with .010 or .020 do that.
 
8

81msw79

Master Mechanic
May 5, 2013
348
60
28
roselle park , nj
#7
I agree with all the statements above. A factory 400 block is notorious for issues once you start punching them out. The walls are thin to begin with compared to other sbc cores. If you need to clean up walls keep it light like 88ss408 suggested. I got lucky with my short block it is standard bore and clean. I am just going to hone it and rebearing bottom end with some new pistons.
 
Texas82GP

Texas82GP

Comic Book Super Hero
Supporting Member
Apr 3, 2015
4,354
3,528
113
Spring, Texas
#8
I agree with all the statements above. A factory 400 block is notorious for issues once you start punching them out. The walls are thin to begin with compared to other sbc cores. If you need to clean up walls keep it light like 88ss408 suggested. I got lucky with my short block it is standard bore and clean. I am just going to hone it and rebearing bottom end with some new pistons.
Totally agree. When I bought my car it had a 400 in it. It was pretty tired. I pulled the heads to take a look. It had already been bored 0.030" and had pronounced ridges at the top of the cylinders. The consensus was it needed to be sonically checked to see if it could take a 0.040" overbore. I sold it and moved on.
 
B

bracketchev1221

Greasemonkey
Jan 18, 2018
217
129
43
#9
Just don't lock yourself into weird engine sizes. Check piston availability for what you want to do in the size you are looking to go to. No point in going to .010 or .020 if race pistons will cost twice as much as shelf .030 pistons. SRP and JE have a large selection of bore sizes for the 400. But I don't know if this is in your budget.
 
L

Link

Not-quite-so-new-guy
Feb 13, 2018
24
1
3
#10
Thanks
 

Similar threads

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot Mike's Montes P-S-T Southside Machine Performance UMI Performance

contact [email protected] for info on becoming a sponsor