The 2 bolt seems a lot more common but should I hold out for a 4 bolt? Right now I just wanna put my vortec heads on it and throw a cam into it (305 spun last night, I need something this summer), but I guess in a few years I'd like to do something wild with it.

Thanks guys, really disappointing killing an engine isnt it?

 

I can't say...

I've never done it.

From what John Lingenfelter writes, the 4 bolt 400 is not as strong as someone would think.

The 2 bolts are more sought after because people can then put splayed 4 bolt caps in them.

I had a 400 2-bolt in a 3800lb. '74 Camaro. I never ran across a car on the street that could beat me. I abused the crap out of that car. I ran it up to 6500 RPMs quite a few times to beat that 5.0 with a Paxton on it.

From my experience, I wouldn't worry about finding a 4 bolt. If I find that Lingenfelter book I bought, I'll post back here later with a quote from him. OK?

 

Definitely, or if you can just give me the title I'll go pick it up Always lookin for a good read! Thanks!

 

The 4 bolt 400 is not as desired for performance build up's because there is alot less "meat" in the bottom end of the block to accomodate the 4 bolt mains. I've seen a few crack in this area.

If you got one, I'd just check it and make sure it isn't cracked, it would be fine for a street / strip build up, but definitely don't hold out for one, since the 2 bolt is easier to find.


HTH

 

From what I have seen the 2 bolt 400 is the better way to go. More strength in the main webbing area. And for a street bound engine with moderate power, 2 bolt mains are plenty strong.

 

Here is David Vizard book, I always order my books from this site.
How to Build Max Performance Chevy Small Blocks on a Budget (Paperback, 2000) ISBN: 1-88408-9348 June 2000
Author: David Vizard

http://half.ebay.com/cat/buy/prod.cg...0491&meta_id=1

 

While the four bolt does have less "meat" around the webbing area, you can add some insurance by going to main studs instead of bolts. Bolts pull more on the threaded part of the main webbing while the studs pull equally on the main caps and the main webbing. I always magnaflux a block before using them. It is great insurance before you spend lots of money on expensive machine work.

 

2 bolt block is stronger...

 

everyone told me the 2-bolt was better. i actually got lucky and the engine i bought was a 2-bolt. still trying to get everything finished up, but i'm nearing completion. swapped out my tbi 305 and 700r4 for a 400 and th350

 

You would be suprized at how many dirt trackers use two bolt small blocks in their cars and make lots of HP and turn them over 8000rpms over and over again.

 

Somewhat related to the subject,
I think people that have not actually seen a 2 bolt main 400 are kind of hesitant to pick one up. I remember my first thoughts of one was a 2 bolt cap set up that looked like 350 mains and had to house the bigger crank and spin the bigger pistons, It painted a scary picture in my mind.
When I actually saw how much beefier the cap design was over a 350, I felt quite a bit more at ease buying one.There are many people that use these 2 bolts and **** them out and never have a problem. I have hit some high RPMS and havent had problems yet, thank ***! I just hope I can afford to have the 2 bolt I am currently using splayed on its next rebuild for extra insurance.

 

the 4-bolts for 400 are actually inferior to the 2-bolts due the the bolt pattern. the 4-bolts have less meat to them and can break easier than the 2-bolts. exact opposite of the 350

 

Look for a 2 bolt "509" casting as they are the strongest.

 

Ill post some pictures off the main webbing so that you can see what the thickness of the webbing

 

I was under the impression that the 2 and 4 bolt 400s were of similar strength. Im also fairly certain that there is a similar amount of "meat" on both 2 and 4 bolt main 400s. I believe the difference is that a 2 bolt 400 can be taken to a machine shop and converted to a splayed cap 4 bolt. That without a doubt is stronger than either a 2 or regular 4 bolt main. Course i could also be talking outta my ***
Matt

 

Let me see if I can make this a little clearer.
The 4 bolt was drilled straight into the block which has less meat to grab onto. Now if you take that 2 bolt and used the splayed mains it will be drilled at a 30-45 degree angle which would give it more meat to hold onto. Good example would be a 4 bolt and drilling straight into a pine tree. Then taking a 2 bolt block, splayed to 4 bolt and drilling into a oak tree at a 45* angle. The oak will give you more meat to hold onto before splitting. I dont know maybe im talking out my A$$.

I will post pictures after I get my camera from my friend.
DTL504

 

thats exactly what im trying to say. nice visuals by the way, pics would be cool too tho.
matt

 

Finally got my camera , here is the photo's off the 400 SBC. this is a 817 block, notice how the middle bosses was NOT drilled for freeze plugs.

 

photo# 2

 

Photo# 3

 

Here is a photo that I found on the internet for the extreme HP/TQ seekers. Looks awesome:

http://www.mjproformance.com/main_caps.htm