Or atleast a build or two with 8.1 swaps? Does anyone have any of those bookmarked? Can't search for 8.1....laaame! 
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Wasn't there a 8.1 swap thread?
- Thread starter Zeus33rd
- Start date
y5mgisi
1 ton status
I know that member "Larry" put one in his 78? K10. He also has a build thread on it over at 67-72chevytrucks.com. Also RyanB and his buddy did one in a truck similar to yours so probably check his posts from about 5 years ago... and check out pacificfab.net that i believe is his shop.
EDIT: Maybe your thinking of this one?
http://coloradok5.com/forums/showthread.php?t=256911
EDIT: also, google will let you search 8.1
https://www.google.com/#hl=en&sclie....,cf.osb&fp=b4f48c618b73e489&biw=1280&bih=834
EDIT: Maybe your thinking of this one?
http://coloradok5.com/forums/showthread.php?t=256911
EDIT: also, google will let you search 8.1
https://www.google.com/#hl=en&sclie....,cf.osb&fp=b4f48c618b73e489&biw=1280&bih=834
I know that member "Larry" put one in his 78? K10. He also has a build thread on it over at 67-72chevytrucks.com. Also RyanB and his buddy did one in a truck similar to yours so probably check his posts from about 5 years ago... and check out pacificfab.net that i believe is his shop.
EDIT: Maybe your thinking of this one?
http://coloradok5.com/forums/showthread.php?t=256911
EDIT: also, google will let you search 8.1
https://www.google.com/#hl=en&sclie....,cf.osb&fp=b4f48c618b73e489&biw=1280&bih=834
Ooooo...Thanks dude. Lots of reading now.
y5mgisi
1 ton status
You betcha! Hope you get to sleep at some point tonight! LOL!
Google search is a good call, never thought of that.
Same goes with all the LS swaps....cant' search LS, 5.3, 6.0, etc.
Is the 8.1 an LS series motor?
Same goes with all the LS swaps....cant' search LS, 5.3, 6.0, etc.
Is the 8.1 an LS series motor?
Nope, shares more in common with a 454
http://coloradok5.com/forums/showthread.php?t=289536
There is a bunch of wiring information in this thread.
The connectors he posted are for an allison transmission control module, btw! Most of the wires run from the TCM to the transmission. There are two that run from the TCM to the PCM and of course the power + ground supply for the module itself.
There is a bunch of wiring information in this thread.
The connectors he posted are for an allison transmission control module, btw! Most of the wires run from the TCM to the transmission. There are two that run from the TCM to the PCM and of course the power + ground supply for the module itself.
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Did someone say 8.1L?? 
I’m the “Larry / DirtyLarry" mentioned in those thread links and can help with any 8.1L swap questions. I did my 8.1L swap in 2008 and have about 12,000 miles on it now from rolling around the back country of CO, UT and AZ since the install. The engine only had about 1,300 miles in it when it was installed. I actually work in the truck manufacturing industry where we built tens of thousands of 8.1L commercial truck and RV chassis since 2000 until the 8.1L was decommissioned in 2011. I've spent a lot of time with these 8.1L engines over the past 11 years in everything from UPS trucks to RV's to mobile command centers. Great engines! Much more reliable than diesel power anyday!
For the first year it ran on a Delphi MEFI-4 ECM batch firing the injectors running speed density calculation like a Marine 8.1L application. I could never get it calibrated quite right so that came off and replaced with a Howell Engine Development harness and P59 ECM running a tweaked GMT800 calibration with a MAF. WOW! Big difference. The 8.1L is a very easy swap as is a direct bolt in just like any non-LS small block or big block. You can even use any exhaust manifold or header from any old big block. It makes big power in bone stock form with just a tuned ECM. I’ve been real happy with the swap. The only thing I don’t like is my current air intake system which I am getting ready to revamp.
Ran a Marine L29 intake on a 454HO with a RamJet 502 ECM for a short while before tossing in the 8.1L. I’ll never run a MEFI4 ECM again! yuk
As the engine looks today. Getting ready to change the air intake though. Oh, and the vacuum brakes have been replaced with hydroboost last year when I did the NV4500 swap.
Recently had to replace the engine mounts for the second time. The Turd Napa engine mounts caved in again driving the oil pan right into the ORD crossmember. Lucky it didn't break the pan!
Energy Suspension engine mount inserts. Much better! ORD Comp mounts are good too!
If you do a 8.1L swap definitly use high quality engine mounts as the OEM replacements are less than sterling and won't live up to this high torque engine.
These or the ORD comp mounts would be the recommendation for an 8.1L. Napa OEM replacement on the right. What a POS.
Here is another nice build thread on an 8.1L conversion into an ’86 C30. Blake did a great job on his swap. I’m totally copying his air intake system if I can get it to fit under the hood. My engine sits a bit high in the saddle due to the Energy Suspension engine mounts so I am not sure the 90 degree elbow to the throttle body will fit under the hood.
My 8.1L swap picture link is in my siggy below.
I’m the “Larry / DirtyLarry" mentioned in those thread links and can help with any 8.1L swap questions. I did my 8.1L swap in 2008 and have about 12,000 miles on it now from rolling around the back country of CO, UT and AZ since the install. The engine only had about 1,300 miles in it when it was installed. I actually work in the truck manufacturing industry where we built tens of thousands of 8.1L commercial truck and RV chassis since 2000 until the 8.1L was decommissioned in 2011. I've spent a lot of time with these 8.1L engines over the past 11 years in everything from UPS trucks to RV's to mobile command centers. Great engines! Much more reliable than diesel power anyday!
For the first year it ran on a Delphi MEFI-4 ECM batch firing the injectors running speed density calculation like a Marine 8.1L application. I could never get it calibrated quite right so that came off and replaced with a Howell Engine Development harness and P59 ECM running a tweaked GMT800 calibration with a MAF. WOW! Big difference. The 8.1L is a very easy swap as is a direct bolt in just like any non-LS small block or big block. You can even use any exhaust manifold or header from any old big block. It makes big power in bone stock form with just a tuned ECM. I’ve been real happy with the swap. The only thing I don’t like is my current air intake system which I am getting ready to revamp.
Ran a Marine L29 intake on a 454HO with a RamJet 502 ECM for a short while before tossing in the 8.1L. I’ll never run a MEFI4 ECM again! yuk
As the engine looks today. Getting ready to change the air intake though. Oh, and the vacuum brakes have been replaced with hydroboost last year when I did the NV4500 swap.
Recently had to replace the engine mounts for the second time. The Turd Napa engine mounts caved in again driving the oil pan right into the ORD crossmember. Lucky it didn't break the pan!
Energy Suspension engine mount inserts. Much better! ORD Comp mounts are good too!
If you do a 8.1L swap definitly use high quality engine mounts as the OEM replacements are less than sterling and won't live up to this high torque engine.
These or the ORD comp mounts would be the recommendation for an 8.1L. Napa OEM replacement on the right. What a POS.
Here is another nice build thread on an 8.1L conversion into an ’86 C30. Blake did a great job on his swap. I’m totally copying his air intake system if I can get it to fit under the hood. My engine sits a bit high in the saddle due to the Energy Suspension engine mounts so I am not sure the 90 degree elbow to the throttle body will fit under the hood.
My 8.1L swap picture link is in my siggy below.
Last edited:
Nah get the DIY4X motor mounts!!! http://diy4x.com/cart/index.php?route=product/product&path=34&product_id=81 
Wow! Nice to see the 8.1 man himself! Larry!
Here are some links to 8.1 threads on CK5:
http://coloradok5.com/forums/showthread.php?t=266850
Mine: http://coloradok5.com/forums/showthread.php?t=264786
Check out post #9 for a bunch of links to 8.1 swaps:
http://coloradok5.com/forums/showthread.php?t=283625
I've been pushing Steve for an engine swap forum - it would be great to get these all together in one place...
Here are some links to 8.1 threads on CK5:
http://coloradok5.com/forums/showthread.php?t=266850
Mine: http://coloradok5.com/forums/showthread.php?t=264786
Check out post #9 for a bunch of links to 8.1 swaps:
http://coloradok5.com/forums/showthread.php?t=283625
I've been pushing Steve for an engine swap forum - it would be great to get these all together in one place...
Mountain_man
1/2 ton status
One issue I'm having right now with my 8.1 swap in the 91 suburban is the ORD crossmember and oil pan clearance just getting the engine in. I would probably put the 8.1 in first then place crossmember into place. I didn't think I would have this issue however I am and now have to loosen everything up and remove a very snug fitting crossmember then try and replace it without screwing up. I'm getting close though!
I know this thread is dead but just in case anyone searches. You have to use the BB ORD crossmember and the engine drops right in Larry recommends a spacer (and I agree) but the engine does fit with the bigblock crossmember without the spacer but its snug.
Also this link http://www.pacificp.com/forum/viewtopic.php?p=111736#111736
Is probably one of the most informative write ups even though its in a newer body style all the GM accessory part numbers are the same. Only difference would be headers (just buy big block headers for whatever truck it's going in.)
Hope this helps somebody. But Larry is truly an 8.1L legend and guru, lol.
Also this link http://www.pacificp.com/forum/viewtopic.php?p=111736#111736
Is probably one of the most informative write ups even though its in a newer body style all the GM accessory part numbers are the same. Only difference would be headers (just buy big block headers for whatever truck it's going in.)
Hope this helps somebody. But Larry is truly an 8.1L legend and guru, lol.
