I am building a 383 w/ an LE2 package and am having the block done locally. Through many problems I recently found that the block is a 2 bolt, not the 4 that I wanted. So, what is the best conversion out there? I've heard of everything from 2 bolt to stud and 4 bolt splayed. Which is the best. My intention is to put together a bullet proof bottem end. Thanks.

Lloyd, you read it right, the block isn't even together. He does have your parts list though

 

4 bolt splayed is very strong, but be sure your cap is a good cap, don't skimp out on your cap. A 2 bolt stud with a good billet cap will hold more than a 4 bolt splayed with a cheap cap. But a 4 bolt with a good cap will hold far more than the 2 bolt ever could.

 

In other words, go splayed 4 bolt, and don't get Eagle (made in China) caps.

 

The problem with 2 bolts is not an issue of anything breaking. It an issue of main cap walk. Go with the extra 2 bolts to keep that main cap still. The eagle main caps arent that bad of a peice. Tolerences on them are pretty good. Seem to hold well.

 

Good billet caps with good studs walk less. But of course a good 4 bolt cat (even non billet) will do better than a billet studded cap. Unless you're getting titanium billet 2bolt caps in which case its probably custom designed and ya may as well go with 4 bolt since it would cost just as much to machine.

 

In a street car I have never seen the actual cap fail, that is not the issue. The advantage is clamp load, and spreading the point of register on the cap out to the pan rails, that is why you run a 4 bolt cap.

Use Pro Gram.

 

If you're using a cheap 4 bolt in a high horsepower application you will tend to flex the cap a little. Thats why I'm saying to stay away from a cheap 4 bolt. Clamping load is affected by a lot of things and stiffening what you are clamping can help some with clamping load.

 

What you need in the way of main caps/bolts is a function of the HP level, and whether you are running a power adder. That's not clear from your post.

 

I have never used the cheap caps, always pro gram or the ones we make.

 

Who does make "cheap caps"? Pro-Gram here too.

 

I'm talking ebay specials.

 

I will chip in on this one, cause I already did my homework.

Program caps are the best.

here is what you need to know from the mouth of programs themself.

This is a response to what caps will work with LT1.


" Are you planning on using the stock dipstick? If so, then you will need a set of our SB350C12 main caps. They are a 12.5 degree main bearing cap that is designed for street and strip use where factory dipsticks are used. You can also use a set of our SB350C22's and they will also clear." If you are planning on putting a sight glass in the pan to check oil level, you can use a set of SB350CSA2’s. These are our most popular caps by far but do interfere with the dipstick. A set includes caps 2, 3 & 4. Please feel free to contact me if you have any further questions.



Then I asked.........
What is the main difference between these two cap sets? I am interested, and trying to decide the best one, for my motor. OBTW these will be good since im going to be using a stock dipstick.

Reply
The SB350C12’s have 12.5 degree splayed outer bolts, while the SB350C22’s have 22 degree splayed outer bolts. Either set will work for your application. The C12’s tend to be a little easier to install.

Then I asked......
is either one stronger than the other based on the installed angle?


Reply


Design wise, the C22’s are stronger. Real world applications though show that something else will fail before either style of main caps.

After all of this I went with the 22 degree splayed.FTW

 

I used the Pro-Grams as well but the shop got me the regular SBC ones which caused dip stick issues, instead of the ones designed for a pass side dip stick.

 

How could I get in contact with ProGram? Anyone have their number handy? Derek

 

Dan Anderson

General Manager

Pro-Gram Engineering

(330) 745-1004