LS swap - Help w/ engine ID for timing chain and sproket replacement.

[lbcoronado]

Hi,

I am new to the site and so far have been getting great help w/ purchases from other members. But I have hit a minor red flag and i am sure someone here can help or lead me in the right direction.

I am doing a swap into my 95 chevy 4x4 Z71. I purchased a LM7 and was told that it came out of an 05 tahoe. Purchased from a law enforcement officer that decided to delay his own project. He told me that he trust who he bought it from and after removing the heads the cylinder walls looked better than I could hope for. The heads are in the hands of TEA for a port job and I just received the new cam (slight bump up comp cam XR265HR-14). But I am not sure that it is an 05 5.3 motor. When I look for a new timing chain set I see PN# differences from 04 to 05 and probably earlier. The following is where I have researched so far:

1) Block: LM7 “2002-2005”
A) Casting #: 12567392
B) Service PN#: 12567393 “2002-2004”, “05” N/A

2) Computer: “2001-2002” red & blue connectors, cable drive
A) PN#: 1220041

3) Intake: “1999-2003”
A) PN#: 25344062
B) 3/8” supply w/ 5/16” return

4) Fuel Injectors: “2001-2007”
A) PN#: 25317628
B) Flow Rate: 3.180 gm/sec or 25.2lbs @ 58psi

5) Throttle Body:
A) 116913B

The engine could be out of an 05 and he purchased an earlier throttle (by wire) and ECU or ? The engine timing sensors are located top back and passenger side lower block location. I want to put a proper timing chain assembly and who knows what other future info this will affect.

Any help would be appreciated.

Thanks!
Brian

[George C]

does the block have provisions for a timing chain dampner? if so then its a later block

also look at the rods if weak rod its an early motor if strong rod later motor

[lbcoronado]

Ok,

It doesn't have a chain dampener but I may have overlooked if there were mounting holes for one.

As for the rods - how do i id if weak or strong?

What would you classify as later vs earlier?

Thanks!

[lbcoronado]

I noticed a typo in my original description (The engine could be out of an 05 and he purchased an earlier throttle (by wire) and ECU or ?).

I wanted to say he purchased an earlier intake and throttle body w/ cable drive throttle w/ matching ECU not drive by wire.

Brian

[lbcoronado]

George C - Thanks!

After more days than Id like to say I traced down this info from your lead:

Our rods are bone-stock powdered metal GM units, P/N 12577583, maintaining the stock 6.098” center-to-center length (as mentioned earlier, with floating wrist pins), upgraded with much stronger ARP rod bolts. These rods were used in 2005 and later LS engines, upgraded to floating wrist pin fitments

The site article had some valuable info including their parts list. I will do a check on the rods today and get back w/ the info

Brian

[lbcoronado]

Oh Yah forgot to list the site:

http://www.precisionenginetech.com/p...-build-part-1/

[lbcoronado]

Well this is the latest. Looks like I will settle on the ID as a gen 3, 02-05? It could very well have been pulled from an 05 Tahoe. There wasn't a provision for a chain dampener and I don't know how to ID the rods (I wished I had the powdered metal rods - ?) without tearing down the engine and that's not what I want to do. There is one other descriptive - all the existing head bolts are the same size. Some "ARP" bolt manufactures call for the bolts to be the same length from 05 and later. Go figure and I'm moving on.

Still putting together parts which are listed below:
wire harness, E fans (will probably buy a champion aluminum radiator), fuel pump, pressure reg., 37 to 42 lb injectors, fuel rails and fittings (want to do away w/ the existing return line), starter, alternator, 4l60e Trans rebuild or purchase from?, flex plate and adapter (95 trans to 04 LS truck) headers along w/ pipe cats mufflers and fittings to weld up, and probably other items I am missing for know.

[George C]

Same head bolts are late 04+

[Duct_tape123]

FWIW, my 2004 has all same length head bolts. Build date shows April 2004. I have an extra set of flex fuel injectors (36 lb) with connectors from a 2005 Tahoe if interested.

[lbcoronado]

Hmmmm. I have wondered why the larger spray "36 lb" offered for the flex fuel as apposed to the 24 lb for standard gas?