So I picked up a 5.3 pulled from a 2001 k1500 truck with the VIN "T" motor. So I have it all torn down and putting it together I ordered the gen 3 head bolts which are the long bolts with the 2 shorter outer bolts. They looked super long. So I took a dowel and ran it down every bolt hole on the mating surface for the head. They are all the exact same length. I'm confused as to why I have a gen 3 block (checked the casting #) with equal depth bolt holes? Has anyone had this experience as well? And if so, do I follow torque specs for a gen 4 block as far as the head bolts?

 

Later Gen III blocks have equal length head bolts.

 

So then should I do 70deg/bolt when i torque them down instead of 90deg for 1-8 and 50deg for 9-10?

 

Torque as you would for Gen IV head bolts. Late Gen III are the same.

 

My ls6 was also weird like that. Gen 3 head bolts but gen 4 cam bearings or some craziness.

 

Call one of the sponsors here that build motors to confirm, but I would think if you had a long bolt block that you would use all long bolts and follow long bolt procedures.

 

I would bet the 2001 truck the engine came out of had a later engine in it. That would explain the all-long-bolt block.

 

In 2004 GM went to the two bolt size head bolts. The two bolts first appeared on the LS6. In 2003 and 04 all 5.7 liter motors used the LS6 block, even though The LS1 nomenclature was used to note the standard 350 HP Corvette motor. The 6 was rated at 405 abd had the LS6 heads and cam for extra power.

This all changed with the intro of the LS2 in 05. Interesting to note that these motors have 4th gen rods, although the rods are referred to as 4th gen and not LS6. For instance, the motor in my 04 GTO is referred to as an LS1, but it has an LS6 block, 4th gen rods, and LS6 intake. It does have the 241 LS1 heads and cam. It is the same type of motor as the base Corvette.

GMs greatest mistake was suspending Camaro/Fbody production for 8 years. For two of those years 2003 and 04, it made either these hybrid motors or the LS6 for the Corvette and later for the CTS-V.

 

I thought LS production started out using the short and long bolt blocks, changing to all long bolts about 2004.

 

You'd think the bolt holes for bolts 1-8 would be about 4 inches deeper than holes 9 and 10. But they are all as deep as 9 and 10.

 

Only thing I can think of. I wouldn't be upset either. Means its newer than I thought!

 

I wouldn't worry about it too much.

It IS what it IS.

Put in what fits and move on.

 

Yes - my 2000 has the two size bolts.

 

Correct.

 

So is it possible I have a block with all short bolts? Because all the way tightened, I have 3 inches before I even begin to contact the head.

 

No such thing as all short bolts. Either 2 short and rest long, or all long.

 

Incorrect. I am looking right at a later Gen 3 block with all 101mm short head bolts. I have both old and new ones right in front of me. Also, from Tick Performance web site; "Gen III LSx engines produced from January 2004 forward have a short style head bolt design, so earlier head bolts WILL NOT fit. Use GM #17800568 for engines produced from January 2004 and later."

 

Well now I'm confused. Maybe late ones are all SHORT bolts, and I got that mixed up. Makes sense though...

 

https://www.jegs.com/webapp/wcs/stor...l=&engine=&No=

 

Thank you! That clears it up! I don't know how I got into my head that late ones are long, since I had seen pics of both sets, plus the later sets are cheaper, being all short.