[speedfreak78]

i am going to build a 400 small block i want either a 12-1 or 11-1 motor something that would run pretty good at the track but still streetable what bore stroke and cam should i go with i want to use 2.08 heads not sure what cc my buddy has a 2bolt main block but i figure i can have it made into a 4 bolt any help will be greatly appreciated.

 

[6NOVA4]

keep it simple and if your on a budget lots of .030 over 400's with stock stroke cranks make plenty of power. With your heads and the right combo of carb, intake, cam and compression with a good set of headers can make 550hp easily.

 

[Stock72Nova]

theres nothing wrong with 2 bolt mains

 

[big dog ss]

2 bolt main blocks are good. just stud the mains and it will be just as strong as a factory 4 bolt block!

 

[Baddbob]

The 509 two bolt 400's are stronger than the factory 4 bolt blocks.
I agree, a simple flat top piston, zero decked, .038-.040 gasket, 64cc heads with good flow and a solid lifter cam with around [email protected] duration and decent lift, with the right intake and headers will make some nice street power.

 

[levisnteeshirt]

i read

a test the other day on a 406 with a 264/270 @.050 solid roller , it made 18 more hp at 11.5 than at 10.5.

 

[bowtie0069]

The 509 two bolt 400's are stronger than the factory 4 bolt blocks

Have any of you ever really looked at the differences between a 2 bolt 400 block and a 4 bolt 400 block? I've heard this for years, but other than the extra holes for the bolts there is NO difference in the main webbing on any of my 400 blocks. Is that the difference people claim to cause the "weakness" in 4 bolt 400's? I'll take any of those lousy 4 bolt blocks if somebody wants to get rid of one! They work just fine for me.

 

[Baddbob]

Have any of you ever really looked at the differences between a 2 bolt 400 block and a 4 bolt 400 block? I've heard this for years, but other than the extra holes for the bolts there is NO difference in the main webbing on any of my 400 blocks. Is that the difference people claim to cause the "weakness" in 4 bolt 400's? I'll take any of those lousy 4 bolt blocks if somebody wants to get rid of one! They work just fine for me.

I've been told many times the outer bolt holes weaken the webbing, a splayed cap conversion on a two bolt block is the strongest as it doesn't weaken the webbing and gives more cap support. At what power level it makes a difference-I have no idea and the bores may just fail first anyway. One local racer here went through quite a few 400 blocks on his 377 engines but the damage I seen on those were always cracked cylinders. He switched to an aftermarket block, gained power, and the failures went away. People seem to think heavy duty when they hear 4bolt main but with the 400's the opposite might hold true.