ToastedPirate

So I'm mid engine rebuild. And I told the shop kid to throw my bolts away before looking to see if I had the same or seperate length bolts lol.

Its a mid year 2004 lq4 from an express.
I'm assuming the bolt length difference is in the block not the heads?

One bolt kit does 1 side. 1 has 2 shorter bolts and 8 long
The other has 10 long.

Which bolt holes are the short ones if it is in the block?

Che70velle

iTrader: (6)

Short bolts will be top row, outside edges. You can use a clean dowel to determine lengths…to see which block you have. 2004 block should be the kit you have in front of you.

ToastedPirate

Kit I have in front of me? That went over my head.

So the top outer are shorter. Any idea how much?
I guess it doesn't matter. Any shorter means shorter means older bolt kit.

01CamaroSSTx

iTrader: (3)

Difference is in the block and it's the 9 & 10 bolt holes which are the short ones. Use a caliper gauge to verify that your block takes the short ones.

Che70velle

iTrader: (6)

My apologies sir…I ASSumed you had already bought the early kit. ARP’s bolt kit would be 134-3609 for the early block. Mid 2005ish GM started the changeover to the all long bolt blocks, which would be…in ARP…134-3610. Just posting part numbers for comparison.

ToastedPirate

Except the swap was 2004. All parts sites show both short and long kits for 2004.
03shows the kit with 2 short 8 long.
05 shows 10 long.
04 express vans show both kits available.

Measuring the blocks bolt holes I have determined mine are all the same length. So 2nd kit.

G Atsma

I thought the later bolts were all SHORT.
Early are (2) M11 x 2 x 100, (8) M11 x 2 x 155
Late are (10) M11 x 2 x 100
As per Summit data sheets

ToastedPirate

Sorry you are correct.

I switched them.
So a question then.
Wouldn't the shorter ones work on all years? If there's no change with the head. Then it shouldn't matter?

G Atsma

Blocks are different. Shorter ones won't reach far enough down in an early block.

Full Power

Was this a " Clean MODEL YEAR" split, with the headbolt lengths, or was there some taper amongst platforms, ie Pickup, VAN, SUV, passenger applications ?

Che70velle

iTrader: (6)

It’s very hit-or-miss. I’ve seen some 05’s with both lengths, both 6 liter blocks. Now ToastedPirate is saying he saw books with ‘04 model year being the changeover year. GM put the leftover unequal length block engines in whatever came down the line in several assembly plants, until they ran out. No telling what you find out there really.

ToastedPirate

Shouldn't matter though
The bolts don't bottom out in the block even with stretch fit, so the number of threads below the bolt shouldn't matter. If it's the newer block or the older design the short bolt still threads in the same number of threads.

Regardless. Mine are all the same length so I need the 2nd design bolts.

Both bolt sets list for the 2004.