Thread: 2 bolt mains

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does any one know what years the good two bolt mains were maid? becase i have seen a lot of stuff about the "good 2 bolts"
i am a bout to switch to a 4 bolt but i dont wanna have to spend more money than need me if im liky and might have a good 2 bolt on my hands any way thanks guys an girls

john

I am guessing u are talking ab0ut a chevy 350 2 bolt block. Most engines are 2 bolt and work well that way. Its possible 4 bolted mains are really overkill for some jobs. First decide what u want your engine to do, then start to gather parts. Hope this helps.

early 327 chevy's were 2 bolt main Dh

283's are 2 bolts.

John, when you say you have seen a lot of stuff about "good 2-bolt mains", where have you seen this??

As far as I know, a 2-bolt main block is a 2-bolt main block. I've never experienced good or bad.

A 2-bolt block will take just about anything you can throw at it up to about 7,000 rpm's and/or 450 hp in my opinion. Above that, you may want to consider a 4-bolt block.

I've never seen a streetable small block that was hurting from two bolt mains. The pistons or cam will go long before you need worry about the main caps.

With the gas available at the pump today, no way you can run enough compression on a street engine that you will pull a web. On a 9 or 10 to one street engine, the 2 bolt blocks will do just fine.

I'm with Tech, far as I know all 2 bolt chebbie blocks are created equal. Good or bad is determined by the quality of the machine work done to it and the skill of the man putting it together.

John, when you say you have seen a lot of stuff about "good 2-bolt mains", where have you seen this??

not so much seen but herd an yes im talkin aobut a 350

Guys correct me if I'm wrong, but didn't some years have more nickel content than others?

Once the oil pan goes on, no one will be able to tell the difference. Build the two bolt and tell everyone that it is a four bolt if it makes you feel better. Only your hairdresser will know for sure.
Ed

Originally posted by NTFDAY
Guys correct me if I'm wrong, but didn't some years have more nickel content than others?

I've heard that too, Ken, but have no idea how to determine high or low nickel content.

I have "Heard" of a similar thing that there was a run of years where the blocks were weaker....but don't know the details.
No matter what could he get a Stud Girdle to bolt on his small block chevy 2 bolt if he wasn't confident in it? Either that or get the block machined for splayed aftermarket mains...which I'm sure would be pricy and overkill on street! Just a couple of suggestions if he's really worried about his block. Anything can be done if you want to pay for it!

I heard that there was a mexican casting or something that was better

Originally posted by techinspector1
I've heard that too, Ken, but have no idea how to determine high or low nickel content.

When looking for a block with a high -nickel, high tin mix, the numbers to look forare "010" and " 020". They are cast under the timing cover area.

what do the numbers on the back of the motor mean? not the casting number, but the ones in the area behind the flywheel.