I did a search and didn't come up with anything conclusive. Will a 2 bolt main block be good enough for a 400ish rear wheel horsepower LT1 w/ a 125 or 150 shot of spray?? Or should I go with a 4 bolt main??

 

Your gonna find both opinions on that. If any doubt 4 bolt splayed is the way to go. You can save cash, but if it makes the motor more solid and less flex prone by the crank, that in itself can save your bearings and make them last longer. You can get by with 2 bolt main as well several people have done it. Your gonna have to research and research until you come up with what is going to work for you.

 

I found a guy wanting to sell a vette 4 bolt main block for $700.00, is this a fair price?? I was thinking of offering him $500.00, what do you think??

 

$700 is a fair price considering how hard they are to find and they don't make them anymore.
I have a brand new one and wouldn't take less than 8 for it.

 

You can do that but you should replace the main bolts with ARP studs.

 

So the same guy offered me a regular 2 bolt LT1 block for $150.00, can I just get that and have it splayed and be fine???

 

That's what most people seem to be doing here.

 

a 2 bolt block with 4 bolt splayed main caps is stronger than a OEM 4 bolt block

I am running a 2 bolt block and milodon splayed main caps

 

Agreed the 4bolt vette block is stronger, but not as strong as a converted 2bolt. I would for sure go with the the 2 bolt block and get it converted if your set on 4 bolt.

 

Not necessarily true. GM knew the LT1 block would be used with STRAIGHT 4-bolt mains, and appear to have put the meat in the block to support it. That's based an an analysis done by a shop that has built more than one 1,000+HP LT1 engine. They preferred a stock 4-bolt block (with upgraded caps, etc, obviously) and had their most successful LT1 build (1,125HP 383 running 20+ # of boost) with a factory STRAIGHT 4-bolt block, and no fill.

 

I just installed a new oil pump today and discovered my LT1 to be a factory 4-bolt main. It is a replacement motor by previous owner and was hoping that it was a 4-bolt. So that means then that I have the stronger block? Are the 4-bolts less prone to spinning a bearing vs a 2-bolt, due to the stronger support?

 

A 4-bolt BLOCK isn't stronger - no matter whether you drill holes for straight bolts or splayed bolts, you are removing material from the block webs, and weakening the block. The advantage in the 4-bolts is strengthing the caps and improving the register on the caps.

 

Nevermind, I did not know that the Vette block had extra material.

 

$700 is crazy. You can buy a running vette LT1 for $750-1000.

4-bolt LTx blocks usually go for $300-400.

 

Yeah it depends on long term goals with the motor. 700 is crazy expensive, but if your gonna go nutz with it, you should be pissing that.