Hey guys I thought I'd run this by yall and see what could be said, I want a 350 in my car and I wann hydro roller cam for it but, I wanna know what is better to go with an older block and retro it or just find a new one, I have access to a 350 4 bolt main thats from the early 70s and high nickel content, or would it be better to just find a newer block?

 

A newer block might save you a little money, since you could use factory roller components instead of somewhat more expensive (although arguably better) retro roller parts.

The older 350 block would work just as well. Don't pay anything extra for "4 bolt mains" and "high nickel content" though. Neither of them in any way makes any appreciable difference in the strength of the block for a streetable application, and the whole "high nickel" thing is mostly a myth anyway.

 

A buddy of mine has one of these blocks. What is the big deal about them, i've never really heard about them until a couple years ago.

 

A lot of people think they have a high nickel block, because of a rumor that's been circulating for years that the numbers "010" and/or "020" appearing on the front of the block near the timing cover indicated that the block was cast with an increased nickel content, leading to a "stronger" block. According to people that worked in the actual foundry where the blocks were cast, the numbers are meaningless, and could appear on just about any block.

It's a moot point anyway, since any increase in nickel content doesn't make the block "stronger" in any way that is meaningful to a streetable engine.

 

I talked to a machinist that took a old style 4 bolt 350 and converted to new style using chevy parts. cost around 175 bucks. can use chevy lifters and tray.

 

For the trouble you have to go through to "convert" a block, its better just to either find a factory roller block, or just use retrofit parts.

 

Well the high nickel to my understanding is because its made from the steel of 30 years ago and alot stronger from the words of my machinist here, and yes thats what I was wondering about was kinda whats best to retrofit the block or find a newer style one, cause so far I havent found any around here, its just gonna sit on a motor stand for a while and get built slow, and I'm sorry but around here we run 4 bolt main blocks, anything else is just a toy

 

The cast iron from 30 years ago is the same as the cast iron from today. Exact compositions might vary slightly from pouring to pouring, but not enough to make a difference. Of the things that actually affect the strength of a block, the metallurgy is way, way down the list.

You can run a 4 bolt main block if you want, it just won't give you any advantages over a 2 bolt block.

 

from what i was told the high nickel block coud be over bored a lot more than the reg 350 block and still mantain stability. the same can be said for a 4 bolt main over a 2 bolt main for a street driven motor with 290 hp a 4 bolt main would be over kill. run 500+ hp on a 2 bolt main and you think its going to be just as stable as a 4 bolt main? i donno but if i wanted to go futher on this you might as well have just said there is no differance on forged or cast pistons.

 

The thickness of the thrust faces of the cylinder walls is what determines how far the block can be safely bored. That's affected mostly by core shift, it has absolutely nothing to do with metallurgy. In any case as mentioned above, the "high nickel" thing is a myth anyway.

The factory made 4 bolt blocks to prevent cap walk in high-load applications, like heavy duty trucks. They don't meaningfully increase the "strength" of the block. If you absolutely wanted to build a high performance racing engine out of a stock block, you probably wouldn't want a factory 4 bolt block anyway, you'd be looking for a 2 bolt block so that you could machine it for splayed 4 bolt caps. At those levels these days though, aftermarket blocks are a vast improvement over used stock blocks anyway.