Forcefed86

iTrader: (4)

Quick sanity check…

I know the “Gen3” engines require the 2 different length studs. And “Gen4” use all equal length studs. I assumed this was due to the bolt hole height in the head?

My last eng was a 2006 4.8 with 706 heads. I used a “Gen4” equal length ARP stud kit. I am putting together what I was told was a “gen3” 6.0 now. It came with 317 casting heads 24x reluctor wheel. When looking at the 706 VS the 317 head I don’t notice any difference in the head bolt hole heights. I had assumed I’d need the gen3 stud kit. Now I’m second guessing myself. Wondering if I managed to get gen4 317 heads? I don’t have a set of gen3 heads to compare it to. Am I missing something obvious? Simple way to tell?

Thanks

RatCityRex

iTrader: (3)

The different length is in the block not the heads. The only way I know that is I got a set of 317 heads and a whole set of equal length bolts and when I put the bolts into the block without the heads on the corner bolts drop in much further than the rest of them before hitting threads.

Forcefed86

iTrader: (4)

Thanks... So the depth on the lower studs is less on the Gen3 VS gen 4 block? Anyone know the depth so I can check it?

old93camaro

iTrader: (8)

what are the chances of having a gen 3 block knock sensors on top with gen 4 stud lenght?

dlandsvZ28

It might be based on the age of the block.

Just got my GM 6.0L Gen III Cast-Iron Engine Block from TSP as a built LQ9 370. . Was told by TSP that the newer GM Gen III blocks require long studs.

Originally thought just a TSP short block to save money because I already had ARP short and long with heads, etc. TSP told me I wouldn't be able to use them.

Is there a way to tell based on a casting number or serial number?

You have PM.

ascastil

iTrader: (2)

Do you have the block? Just stick something in the bolt holes like a straw to see how deep they go. If all the same then you'll know.

FWIW, I have an 04 C5. I bought ARP equal length studs and it was wrong. For some reason my block has the 2 different lengths. If you try to bolt the heads down with the longer studs they just won't go in all the way. Youll know if you stick something in the holes.

JakeFusion

iTrader: (7)

04.5+ Gen III are supposed to have the all short length head bolt length. So you can certainly have knock sensors in the valley with short-length bolts. For example, all the L33s came that way and they were made until 2007.

Suncc49

you dont have a box of old head bolts? heh I have about 60 or 70 laying around now...

ascastil

iTrader: (2)

Good to know. That explains why my 04 had 2 difft lengths.

3 window

iTrader: (1)

ascastil

iTrader: (2)

Him, idk why but the bolts stopped. Bought the different length ones and it was fine. Oh well, cars been up and running for some time now. Too late to investigate.

one fast zo6

iTrader: (490)

only four bolts are different ! Two outer large bolts on each head.