No way look below at how close they are to the cylinders and headbolt holes. You would be asking for a crack to develop.

Roby

Offshore addiction really hit on a big problem. Now that I think about it, If I had 400SBC on a boat I would definitely use a closed cooling system

Roby

Thanks guys, Would it be better to build a pair of 383 than to go with the 400s? I would do a pir of big blocks but, my boat is already set up for the small blocks. I am hoping to be around 400-425 hp once done, and still be reliable. Thanks again and appreciate all the in put.

One more thing
 

Don't use head studs on a 400. The bolt hole is so close to the cylinder wall that the shoulder of the stud against the deck will create fatigue over a long period of time and end up with a crack. Saw 2 blocks that this happened to.

One other small issue even if you build a 383 is that you are somewhat limited on your cam size. This is do to interference between the rod bolts and the cam lobe. This problem will be even more pronounced if the mains have been align-bored

Roby

WOW all this block talk has gotten me wanting to build another super mouse motor :)

I have read that you can now get small diameter cams so you will not have the interferance problem. I am interested in this because I currently have 6.2s and I could either build on what I have or use the 400s that I have readily available. I think I could use some of the 6.2 parts on the 400s.

I think you need to use the 1.6 or longer rockers with them though. Then again you are probably talking about somehting different.

Roby

A small base circle cam and/or H-beam rods will eliminate your cam clearance problems. You can buy rotating assemblies (internal balance) now with a cast crank, 6 inch H-beam rods and SRP dished pistons (great for quench) for about $1000. The only possible grinding you will have to do then may be for the rod bolt clearance around the oil pan rails.
Hope this helps,
Bob

I had to grint the stinking (you know what) out of my rod bolts to clear cam lobe and pan rails. Keep in mind that this will weaken the rod bolts and do wonders for the balanced assembly. Really no getting around it.

Roby

The H-beam rods use cap screws instead of rod bolts and nuts eliminating the need to grind any of the rotating assembly. Just the oil pan rails, and very little there.
Hope this helps,
bob