small block 400

[bigsnookmaster]

If your'e going to bore it, make sure it is honed with deck plates. This will insure a round hole after the heads are torqued. I believe this is especially important on the 400's because of the thin walls. As 406 Q-ship said, use the longer 5.7 rods. I have been running the 400's for over 15 years with no overheating problems. I also don't run them with the steam holes.I have the steam holes plugged, and deck the block to eliminate them, and I know alot of people say you need them, but I have had no issues. I would read up on different 400 builds, and combo's, before you start buying a bunch of parts. I would also consider what you want the engine to do and contact the cam manufacturer of your choice to get a recommended cam. I've had alot of luck going this route. Good luck on your build, and you will be smiling from ear to ear the first time you hammer the throttle! I promise!

[big_al_71]

I have to agree with Greg. My big small block 400 has had me smiling for over three years.

[C-10 simplex]

What's the mpg difference between a 400 and a bread and butter 350? Say an L48?

[406 Q-ship]

Originally Posted by C-10 simplex

What's the mpg difference between a 400 and a bread and butter 350? Say an L48?

The MPG difference isn't all that much, just with a 400 a taller rear gear can be be run. With the taller gear the 400 does not have to work that hard to get a heavy truck to speed (less throttle=less fuel) and the lower RPM will get the MPG and engines last longer. An L48 is not really a bread and butter 350, that is the Corvette 350 in the mid-1970s. The L65 is the pedestrian 350.

[BIGBLU 72]

for got to play with my vortec headed 406 this week and love it! it acts like a BBC with tons of torque way down in the RPM range! i went with LS6 beehive springs and a Lunati Voodoo bump stick on the vortecs and have zero problems! im gunna have a hard time keeping tires on my 68

[BADPURPLE70CHEVY]

Originally Posted by BIGBLU 72

for got to play with my vortec headed 406 this week and love it! it acts like a BBC with tons of torque way down in the RPM range! i went with LS6 beehive springs and a Lunati Voodoo bump stick on the vortecs and have zero problems! im gunna have a hard time keeping tires on my 68

I have had had 2 big blocks. A 396 and a 454 and my 406 is way funner to drive. Lots of torque.

[68Gold/white]

Originally Posted by BADPURPLE70CHEVY

I have had had 2 big blocks. A 396 and a 454 and my 406 is way funner to drive. Lots of torque.

Rev's like a small block, torques like a big block...

Vortec heads are what most seem to use, I know they are good heads. 487 and 441 heads are also great heads for a 400

[PHAT TONY]

If you go with a "big" cam you need to watch clearance with rod bolts; roller cams and some solid cams offer a smaller base circle. I'd steam hole the heads for a little insurance and a 7/64ish hole drilled in the thermostat just to keep a little bleed going; worked for me for years (and lotsa tires too).

[bigsnookmaster]

I run a .900 base circle in mine with .578 lift, and a 215cc Victor jr head. It's all about the combo, and what you want out of it. They will take more camshaft because of the extra cubes. Gotta love them 400's!!!