rang-a-stang

Sigh... GM 12563533 is not the correct fastener. That is the fastener for the 6.0 when using a spacer. I am not sure why it is so hard to find data on this. I know the 8.1L is all metric so the crank flange should be metric. the next part number I have is GM 11609297. One website say it is M11X1.5X25-20. If I were home, I would go check but I am on travel until mid March. Can anyone verify either of these (if 11609297 is the correct part number and if M11x1.5x25-20 is the correct measurements)? I am hoping to order bolts so they are waiting for me when I get home.

strutaeng

Hey, I removed one of the bolts from my engine. Just keep in my that flex plate is for the Allison, but maybe they are same for the 8.1/4L80e combo?

I hope this helps.

rang-a-stang

YASSSS!!! Exactly what I need! When I get back to my hotel tomorrow I should be able to use those specs to find the correct bolts!

rang-a-stang

Went to a local wrecking yard today and pulled the flexplate bolts out of a mid 2000's 5.3. I don't have a way of measuring them right now, sitting in my hotel room, but I will take one with me to a store with a caliper to measure them this week sometime. However, the ones from the 5.3 are slightly shorter, the same thread, and seem to be the same width. Pretty sure these are the right guys. Just like yours.


Once I clean these up and go to install them, what do I use as thread locker? Just blue locktite? Or should I use RTV? (again my first Chevy engine so sorry for the really elementary questions)

Next dilemma. My 8.1L is a work horse and the oil fill tube lays across the engine bay.


Looks like the oil fill tube I want is GM 12581140. This is the S Shaped one for the later model intake. BUT NO ONE has it in stock. Mercury Marine has part number 864996 which is a straight tube but it is also very hard to find. I have one saved in a cart on some mundane boat website but i am 90% sure as soon as I order, I will get an email saying its not actually in stock and they will refund my order..

One yard I went to out here had a Kodiak with an 8.1 but it had the same oil fil as mine. I'll keep watching fleabay and will check my yards back home when I get there. I don't need it this instant so I have some time.

strutaeng

Blue Loctite Is what I've used on the LS engines, probably same here.

That's a strange looking oil fill tube. Mine just has it there, but comes straight up. It looks like it comes from the aluminum intake, which is kinda weird but I hadn't paid attention to it.



Also, is that the air compressor pump there off to the left/top? The 8.1 in the pickups have compressor on the passenger side, down low by the frame rail, just the LS engines. Not sure if you are even going to run AC, I'm just curious.

rang-a-stang

Yeah, I think this is the normal fill tube for the work horses and the Van installs. There is a rubber hose that goes on the end of my metal tube that puts the fill cap up on the radiator support. Your straight one, I think, is the factory one for the earlier Avalanche/2500/3500. I read somewhere that it interferes with the later throttle body. If I can't find an S-type fill tube I'll just fab something up.

Copy, blue Loctite. I'll probably do the same.

Yeah, that is the A/C compressor. It's nice and high but it lays Waaay over the starboard side (along with the Alt). I have a feeling it will interfere with my stock battery location but I will cross that bridge when I get there. I want to keep it on there for a later A/C install but right now i am 100% focused on getting the truck on the road. I'll figure out A/C later. Interesting fact; the fan is hung on an idler pulley. The water pump pulley is threaded for the fan adapter and I plan to mount it there when it goes in my truck.


Another interesting fact, everything on my motor has shown me it is a later model motor (cam sensor, no EGR, later coil packs, and my throttle body) but my fuel rail is a return style like the early ones. I am kind of stoked on that! I may have to plumb a return line but I won't have to plumb a pressure regulator. I plan to run poly lines so that saves me like $75 in pressure regulator and fittings.
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The Kodiak at the local Charleston yard with the 8.1 has the A/C compressor up near the throttle body. I am going back to today because I also need a dust cover/inspection plate for my 4L80. The correct factory part number for the dust cover for an 8.1/4L85e is 19259119 but the best price I can find is well over $200. I AM NOT paying $200 (or even half that) for a dust cover. I'll just get one from an LS, SBC, or BBC and make it fit.

strutaeng

Interesting.

My engine is from a 2004 pickup (...or so I was told. I do have the ECU to confirm) and it does have the EGR system. It's also drive by wire. I can't remember if it has return or return less fuel setup.

Edit: it's return

I'm sure the engines for those really heavy vehicles were emissions exempt, so that probably explains why you don't have EGR.

rang-a-stang

Went back to the wrecking yard and looked at the 8.1 in the Uhaul they have. This is the oil fill I have; notice how nice it is for filling when in a Kodiak/Topkick but awkward it would be for us.



Also took a picture of the nice high mount A/C and the belt routing in case any one else wants it. This one has the earlier DBW throttle body.




I agree, @strutaeng , who know what smog laws these work horses did/did not follow. There is a plate over the EGR passage on the back of my intake manifold but my exhaust manifolds do not have a provision for the tube.

Yesterday I ordered $150 in Front/rear main seals, oil pan gaskets, oil filters, spark plugs, Trans input/output seals, pan gaskets, filters, etc from Rock Auto. I ordered mostly GM parts but a few other aftermarket parts, too. I also picked up a dust cover for the 4L80E from an LS equipped GMC Van while I was at the wrecking yard. My fleabay oil pan from an 8.1 Truck has arrived at home already, as has the starter, flexplate, and bellhousing bolts. My list of items needed to install the motor is getting short. Notice I said "install the motor" not "start the motor".

shakenfake

Lol at install the motor not start the motor

rang-a-stang

Finally had some time to run over and measure the flywheel bolts that came in my 8.1 and the flexplate bolts I pulled out of the 5.3 in the yard. Notice the flywheel bolt IS significantly longer. Also notice the LS flex plate bolt is the same length as yours, @strutaeng . I think the difference in the width between mine and yours is because of the way he measured it (the dude at Napa wouldn't let me borrow his caliper and insisted only he touch it, even though it was falling apart). I feel good about these.




I just ordered a new 1 ton engine stand. I am also watching craigslist/marketplace for a used 2 ton engine hoist. I think the only parts I have left to buy are oil cooler lines, an oil cooler, oil fill tube, Oil filter (Baldwin B1428), and trans dipstick tube seal.

Don't laugh but the long block will be painted AMC blue. Why? Cuz my truck originally came with an AMC motor, I have 2 half empty cans of AMC blue spray paint on the shelf I want to finish them off, and I like it/it's my truck. This was my 401 in my Chief and I plan to paint this engine in the same combo/theme/syle except I will probably leave the intake raw aluminum..