The long block that I got this weekend is a 2 bolt main and I was really hoping it would be a 4, that way I could do a 383 stroker. I have heard from several friends that you can convert a 2 to a 4. Is there such a kit and where would you find it??

 

I'd do a splayed billet mains. has 4 bolts and is hella strong also i believe it requires a 2 bolt main block to do this so you should be good.

 

Any good machine shop can convert the block to a 4-bolt. The strength difference between a 2-bolt and traditional 4-bolt is not that significant as you remove much metal to make room for the extra bolts. Make sure that if you are going to convert to a 4-bolt you go with splayed main caps as the splayed bolts are exponentially stronger then the traditional bolts.

 

how much power do you plan on having? a two bolt main block can support 550 to 600 hp.

 

not being funny but bluecajun is right, I have never seen a crank fall out of a block!!! 2 or 4 bolt

 

Milodon is around 250-300 for the splayed caps last time I had some done. CAT sells some cheaper ones for under 100 but I cannot speak for the quality. They are right 2 bolt is fine for most. You can use a girdle and studs. At some point you stress the webbing of the block(pull the caps out of the block) with even the splayed main caps. You can only get so much out of a production block before the bores start distorting and other problems occur. If you're want tons of HP find a bowtie, or aftermarket block.

 

Milodon makes a kit like they said. It would have to be line honed afterwards of course. But also like said above, the 2 bolt will hold up just fine to 550hp+. The 4 bolt from the 60's and 70's was way overkill.

 

I happen to agree with all of this: 2 bolt will be fine as long as it is built to last. Now if I was going to add nos, charger, or turbo, the 4 bolt would be superior.

 

As mentioned earlier... Milodon makes a nice splayed cap kit. What year is the long block you picked up? May want to check that and make sure it has the lifter valley set up to accomodate roller lifters which is what I am assuming you'll go with. GM also has a nice piece...10105123 not too much more than buying aftermarket main caps and then paying a machinest to install them... although a splayed cap block can take more abuse. FWIW, I used the GM block on a 383 buildup for my 85 Vette and couldn't be happier...

Bill

 

I was told that the block came out of a 94 chevy. I checked the #'s on the block and went to mortek.com to verify. I want to go to a 4 bolt because I was informed that you must have a 4 bolt to build a 383 stroker. Is this true? Someday I plan to add a charger but that will be a ways off. My goal is to have about 375-400rwhp, all motor. Who knows what it will be after the charger install.