hey guys I have a question and I cannot seem to find any information anywhere I traded a 454 for a 6.0 and a sbc 400 both complete and the 6.0 came with harness and pcm. I was going to re-build both and put the 6.0 in my El Camino but it just looked a little bit off to me so I grabbed my 4.00 ring compressor and guess what it doesn't fit the 6.0 block bore. I mic'ed it and it comes out closer to a stock ls1 3.8 bore I don't remember exactly what it was off the top of my head. Does anybody know anything about this engine my guess is??? I was hoping to just hone the walls put some ls2 flat tops and go but now I am like WTF. any help would be greatly appreciated. The pistons are dished with a cross pattern relief in the head of the piston.

 

You might have a 5.3L. It should say on the block either 6.0L or 4.8L/5.3L.

 

it sys 6.0 on the back right on the block.

 

its really weird I have built a 6.0 before and did used to be a Corvette Tech back in 05 but this thin just seems off I was thinking 5.3 as well but somebody would have to had been pretty creative to make this 6.0 casting id look right I will try and post a pick from my IPHONE.

 

 

How are you measuring the bore size?

 

well with an inside mic but I also have a 4.000 machined aluminum ring compressor that I use on all my 4.00 bore engines and it doesn't fit the cylinders at all.

 

How are you measuring? At the top, middle, bottom? Have you tried measuring 90 degrees apart? Is the area you're measuring clean and not built up with carbon/etc? Are you 100% sure you were reading the mic correctly?

I'm not trying to insult your intelligence or anything, but all GM 6.0L engies are 4.00" bore +/- a couple thousandths of an inch. I think it's more likely that the measurements were off or that something is up with the ring compressor rather than you acquiring a unicorn engine.

 

yeah I will re-measure it tonight but I was measuring about an inch down in the bore and AS far as the ring compressor goes it doesn't have any burs or anything on it. I have been reading MIC's since I was about 6 years old if I would have stayed in the industry I would have been a third generation Chevrolet Mechanic.

 

Looks like an lq4 to me

 

lol looks like one to me too DietCoke just the bore size is smaller I will re-measure it tonight when I get home and post those readings.

 

That's not a 5.3, there is too little space between the sleeves. 5.3s have almost an inch of meat there.

 

5.3

 

The cross top pistons were in LQ4s in 2001-2

 

It is supposedly a 01 so I am wondering if it is just a tight finish hone or something I will mess with it some more tonight I may even take the sb400 off the stand and put this one up there to tear it down.

 

It may be completely stock bore, but there's no way a 6.0 block would have a 3.8 bore...that's a 5.3. And it would be pretty hard to take a 6.0 block and make it a 3.8 bore without it looking very obvious. So unless you clearly see some new liners in there from being re-sleeved then you're just measuring wrong.

 

redtan I appreciate your input like I said I am not 100 percent sure what the measurement was but I know I was under 4.00 I will remeasure tonight and provide pics also the 4.00 ring compressor I have is specifically made and ordered threw summit racing for the LS 4.00 factory bore and I have used it several times before on other blocks 04 and up as I have a cam bearing tool and replace bearings and re-ring or rebuild bottom ends for people I know so I have built more than 1 or 2 of these. LOL every body can have an off day and I will recheck tonight but when the ring compressor didn't drop in the bores it confirmed to me that my measurements then were correct.

 

You would be able to see .200 with a scale.

 

Ok just measured it again and it is roughly a 3.982 bore measured 10.112 cm with my mic and calipers

 

I will take those mic reading lessons now lol





Lip in on one side of the bore out on the other!