I see a lot of guys getting ther 6.0l's 30 over to make them 370. Why not just run them stock at 364? Is there really going to be that big of a difference?

 

Maybe the walls are scored and they need to be bored to get a good seal.

 

I had my iron block just honed to be perfectly straight and left it 4 inch.I wanted all the cylinder wall strength I could get so it will just be a 402 instead of 408.

 

I was thinking the same thing but nobody ever mentions the reason why they are doing it. I was just going to leave mine alone incase I did hurt it and needed to fix it later.

 

That is the same for me but I am just goint to run a stock strock.

 

I'd just talk to the machinest and ask what he suggests.

 

All of the LS2 guys just hone them because they dont have enough cylinder wall to bore.I guess its just personal preference.

 

Back when people started building 6.0 iron block motors, they were only using seasoned blocks (used blocks) so it was common place to bore a block +.030" So the 370 and 408 names remained popular from that. My take on it.

 

My block was bored .030" over because I bought used pistons (i'm a cheap bastard) that were setup for .030"

That is my only reasoning for having a 370.

 

x2......

 

mine is a 366...

0.010 over

 

My thoughts exactly I got a new LQ4 block, line honed it, and went from there.

Keith

 

Hmm well iron blocks are totally safe for 408 and not sure how much bigger. Was a bit worried 427 on iron block might be too much overbore for higher boost so stuck with 408 and also it was cheaper and figure good enough for my power goals.
Its a bit cheaper to go with a 370 and you can use stock crank and guess most guys would bore it out anyway especially if the engine has some miles on it.And more displacement is more torque,faster spool up and more potential power.

 

i went to my shop (TRT) and i was paying them to do a 6L block and make it a 370, but they told me that they were gonna use my stock crank and if i wanted to sell my old motor that they would need $200 for another crank...... i asked him how much would it be for a forged crank and he said between 7-900 and i told him i might as well save him the trouble of removing my crank from my old motor and just keep it in there and buy a forged crank and make it a 408 instead of a 370 . my dream has always been to have a 408 turbo camaro since seeing the success of people on here with that set up

 

Yep good choice.If you are going to a forged crank anyway might as well do a 408. Welcome to the 408 club.

 

Thanks for everyone info. Atleast I know the reasons now.

 

Lots of engines are .010 - .020 over too, just depends on the builder, condition of the block, and goals.

I had an NA iron block that was .060 back around 2000, not too many blocks can be taken out that much due to core shift.

 

I'm going with a 370 because I wanted to use my stock crank. Plus, I'd easily be within my HP goals with it.

 

mine is a 365/.005 over