Swapping a 6.0 ls into a G body

[johnnunez29]

Exactly.


The post above another guy sees it as well. You say two different things.


Pretty sure even the small bore LS7 Heads from MAST need a 4" bore.

If this guy is building something with a 3.900 hole in it, cathedral head all day but we shall see..

The heads I have are the small bore ls7 heads.

 

[johnnunez29]

Soo what one is it?

My apologies. Didn’t realize I wrote it wrong. Think the engine has a 4.000 bore from factory. Unless I sleeved it maybe lol. But no it’s a 4.030 bore and a 3.900 stroke

 

[Built6spdMCSS]

Ok that clears it up. Yea you can take a 6.0l factory block .030 over with no issues.

I built a couple of 408ci setups, but that was a 4.030" bore, 4.0" stroke.

 

[johnnunez29]

Ok that clears it up. Yea you can take a 6.0l factory block .030 over with no issues.

I built a couple of 408ci setups, but that was a 4.030" bore, 4.0" stroke.

pretty much what im doing. only went 3.900 stroke because l8t crank comes in that and less travel in the cylinder. Some of info i found said it is a safer stroke for the cylinder walls. Something about ovaling due to the piston coming out too far tha the bottom. guess ill find out .

 

[Built6spdMCSS]

The Piston does travel down a hair too far and it rocks on the skirt. I'm curious how much a difference that 3.9 Crank would be.

 

[johnnunez29]

The Piston does travel down a hair too far and it rocks on the skirt. I'm curious how much a difference that 3.9 Crank would be.

sh*t. Me too lol. From my reading looks like the ring will stay completely within the piston. May not be too much a difference. Guess we’ll see. Should be a longevity thing more than performance .

 

[64nailhead]

sh*t. Me too lol. From my reading looks like the ring will stay completely within the piston. May not be too much a difference. Guess we’ll see. Should be a longevity thing more than performance .

Long stroke is not longevity prone. Especially with a 2618 piston at .005-.006" piston to to wall clearance. Ask me how I know.

 

[johnnunez29]

Long stroke is not longevity prone. Especially with a 2618 piston at .005-.006" piston to to wall clearance. Ask me how I know.

Would 3.900 be considered a long stroke? Stock is 3.622. Most my reading lead me to 3.900 being a bit safer than 4.000. Obviously not bullet proof.

 

[64nailhead]

Would 3.900 be considered a long stroke? Stock is 3.622. Most my reading lead me to 3.900 being a bit safer than 4.000. Obviously not bullet proof.

You'll be using a short skirt piston which is much more unstable in the bore than a conventional piston. What piston are you planning to use (part number)?

 

[johnnunez29]

You'll be using a short skirt piston which is much more unstable in the bore than a conventional piston. What piston are you planning to use (part number)?

No clue. Wiseco . Had to be semi custom ordered. Ordered through mast, said it was 6 wks leed time … almost 7 weeks ago 🤷🏼‍♂️