Jump to content

8.1l Heads Questions

TravisAZ

Recommended Posts

TravisAZ Enthusiast

TravisAZ

Posted
Posted

Hey guys - This is pure speculation at this point, but I am trying to plan my options. Vehicle is a 2001 YukXL 2500 4x4 with the 8.1L around 120k mi.

 

I am losing alot of coolant and don't know where it is going. I am going to pressure test it this week, but I am expecting at best a head gasket and at worst a cracked head. I didn't think the castec problem applied to the 8.1L, but I don't really know much, so whatever.

 

Anyway, I know the heads for the 8.1L are odd and there is no after market for them. The motor has ~120k on it, so if I am going to go as far as pulling the heads to do gaskets, I might as well rebulld them if rebuild-able or replace them if not.

 

Of course, if I am going to go that far, I might as well do a cam and some headers while I am that deep into it. If I am going to go THAT far, I might as well just rebuild the whole freaking thing, right? While I would love to Im not sure I have or want to spend that kind of coin on this truck.

 

So, Questions:

 

1.) Raylar is the only option for after market heads, right? How about intake manifolds?

2.) If the heads are ok, what cam/rockers would you guys go with? Vehicle is used pretty much for towing.

3.) What should I expect to spend if I take the heads to a shop for a port and polish and then rebulid myself?

4.) What tests would you perform on the bottom end of the engine to feel comfortable not pulling and rebuilding it while doing the top end? Im pretty handy, but space is going to be a big issue here, because this beast probably wont fit in my garage, and I am far from having a well equiped shop. Mechanics are awesome, but I usually can't afford them. I know my limitations, but I try to do alot of my own work.

5.) Would I get much out of headers with this motor + towing cam?

6.) Any good sources for reman'ed heads out there?

cliobogger Enthusiast

cliobogger

Posted
Posted
www.Dartheads.com has cylinder heads for the 8.1 at $670 per head. They also make stronger blocks.

 

 

that hopefuly dont eat oil like crazy. OM NOM NOM :thumbs:

Riverjet502 Enthusiast

Riverjet502

Posted
Posted

I would just port match the heads to the intake.. (polishing the heads is a waist of money since you will never see the rpm to take advantage of the polish).. Maybe some bigger valves. Call a few of the cam companys and be honest with them to what your desired results are. And long tube headers. Now that sounds great, should see some good results.. But now can your PCM support these mods? Definitely need to call Justin at Black Bear and talk with him about some software changes...

yukon25008.1 Senior Enthusiast

yukon25008.1

Posted
Posted

I have an 8.1 out of a wrecker/tow truck, was going to put in an old truck. just dont have the time or cash right now to play around. the motor only has 47,000 on it. my motor guy looked at it when i first got it, and said everything looked great..and it didnt even look like it had 20.000 on it. this would save you a fortune on parts,labor,machine work. any of that raylar or aftermarket marine 8.1 stuff is SO high in price.

Let me know..im letting go pretty cheap

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • Newduramaxh*ar
      DTC P2C48 auxiliary cooling pump

      By Newduramaxh*ar · Posted

      I tried tapping it.  This might sound like a dumb question, you should feel vibration or some type of noise when it turns on? Can someone please verify? Thank you all!
    • Chuck FB
      first oil change - 2026 2500HD gas

      By Chuck FB · Posted

      I feel better now for my own view point and actions or lack there of towards the dealership service theme reading your post and others. GM corporate is who offers the two free oil changes on the HD trucks and I bought my truck in Feb of 2025 and those oil change offers run out within 2 years I believe and I highly doubt I will be using either one of them. I had asked if I could officially give those free services to another customer ( a friend ) and they said no, its all a GM corporate thing based on the vehicle in question. What that service advisor did however was go into a little story about how such and such customer was denied engine warranty because he had done his own oil changes because then they are not documented ... you see where that goes and so an employee playing the game of scaring the customer into having the service work done there most certainly triggered my thought process. At a later date I did talk to the person who handles warranty claims at the dealership and she said to be sure to document the oil changes and keep receipts for the oil and filter ( coped the receipts from cases of Mobil oil and case of filters I bought from them ) and the vehicles VIN, the date of service, mileage etc and staple that together as a record I would give them if that was ever needed and I keep my own log book for services for each vehicle as well. Oh and about 8 months after I bought the truck the dealer starts calling me to offer a maintenance service since they haven't seen my vehicle show up on their system ... for the mere fee of 300.00 Canadian to change the oil and rotate the tires and a few other minor checks and I declined the offer, I get the call again a couple of months later for the same thing and she could tell I was not interested and she asked if they should take my name off the call list and I said yes, do that !.    By the way did you happen to keep your factory oil filter to open it up and see the surprises inside as I expect some will show up as per the odd little sliver of metal shaving and particles that the filter does trap along with bits of grey silicone sealer that come off of the inside edge of mating surfaces. I have cut open every filter so far on my truck although few miles but have changed the oil often and the second filter was vastly better with very little of anything, that first filter was the unsettling one as I expected it would be. 
    • OnTheReel
      OCI, not when but why?

      By OnTheReel · Posted

      I get why they do this…but man…not ideal. I only extract on inboard boat engines because the drains are buried and even then I hate it because it’s easy to leave a quart behind with that method.   They should market it as an “oil refresh” not oil change!
    • KARNUT
      OCI, not when but why?

      By KARNUT · Posted

      I only get oil changed where I can watch. Valvoline pulls through the dipstick into a see thru glass. When done they show me the dipstick. About the only way they can mess up is using the wrong oil. But that secret wouldn’t stay secret long. Honda uses TQ wrenches on everything. You can watch through a plate glass window. Discount tires does that with tires. Trust but verify. 
    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      I would not argue that with you. It would be pointless to argue against the truth and you speak the truth.    My question and in fact the entire point of this thread is an exploration into the levers of wear which happens no matter how well we maintain our powertrains.    Some of these levers we exert a good deal of influence over which can and do result is lower wear, longer powertrain life. Some others we are sort of stuck with.    An engine is typically done when the ring to bore seal no longer is able to do the job effectively. Normally the first thing to go in a engine otherwise well maintained and adult driven is this seal.    Looking into the means, methods, products and attitudes that influence the rate of wear seems a worthwhile inquiry to me.     

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...