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L18 8.1L swap resource thread

Are you running one of their PCM's too? If so, I'm interested to see how that works for you after all the issues I had with their tune.
I have my stock pcm from doner . Had local guy turn off stuff and 1:1 pedal mod for dbw . Just need to get it all together now .
 
Are you running one of their PCM's too? If so, I'm interested to see how that works for you after all the issues I had with their tune.
Yes. Sent a core, asked for max power, no egr, no torque management, manual trans. Keeping my fingers crossed on the tune.
 
Yes. Sent a core, asked for max power, no egr, no torque management, manual trans. Keeping my fingers crossed on the tune.

DBW or cable? I didn't ask for max power but otherwise the same with a cable t-body. Tune was all fk'd, had to buy HP Tuners and disable a bunch of crap with the help of CK5.
 
DBW or cable? I didn't ask for max power but otherwise the same with a cable t-body. Tune was all fk'd, had to buy HP Tuners and disable a bunch of crap with the help of CK5.
Cable, 7.4L throttle body. Pretty much the whole Larry recipe from this thread. Hope they have the tune figured out now.
 
Cable, 7.4L throttle body. Pretty much the whole Larry recipe from this thread. Hope they have the tune figured out now.

Same deal with mine.... I hope you have better results. I even bought a second PCM from them to rule out a hardware issue. All of this happened last July and August.
 
Same deal with mine.... I hope you have better results. I even bought a second PCM from them to rule out a hardware issue. All of this happened last July and August.
What did you have to change in the tune? What were the errors while driving? Should I buy HP Tuners? I probably have an LS Jeepster build in the distant future so its not just for this project. I didn't really want to get into tuning which is why I went this route with the 8.1L and ProFlo4 on my other big block.
 
What did you have to change in the tune? What were the errors while driving? Should I buy HP Tuners? I probably have an LS Jeepster build in the distant future so its not just for this project. I didn't really want to get into tuning which is why I went this route with the 8.1L and ProFlo4 on my other big block.

It was fouling plugs and falling on its face during acceleration. It’s all covered in my build thread but I ended up modifying a bunch of settings and it ran 10x better. It was frustrating because I went with the Howell setup to keep it simple however it ended up being more complicated than it should have been.
 
No he already had it out. I’m going to go through it and do rings and bearings anyway. Hopefully thats all it needs.
 
you dont need to do that on a 8.1 . there 300k mile units . but up to you . i would do gaskets and clean up . if doing rear main it takes the special tool kit . head bolts are 1 time use . and torque to yeild so angle gauge to do new ones unless arp style . i would pull plugs and look in with a good scope . if all clean and good RUN IT .
 
intake mod and valve cover gaskets, egr delete, updated crank sensor. maybe valve springs. run it
 
Broken starter boss but it has 4-5 threads of engagement. Dirty but it looks right for a 200k mile engine. Rear main leaks, so its getting all gaskets, Egr delete, etc. Newer throttle body and the oil is used but no water,the plugs look good and it rotates smooth. I feel like a need an 8.1 t-shirt or a patch now.IMG_2199.jpegIMG_2198.jpegIMG_2201.jpeg
 
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1qrt atf in place of 1 qrt oil and drive 500 miles . 2 or 3 x and it will clean out that sludge .

As to the starter boss broken few options . But i would clean it up good and post more pics with a starter on and bolted tight .
 

Well I am doing my intake, is leaking coolant? pass rear corner.
Got new arp bolts awhile ago. Double checking for correct length found above link.
These are the bolts I found20250301_105733.jpg

So which to use ?

I also have 2 different gasket sets, one GM and one aftermarket
20250301_105946.jpg
 
For headers, what's going to be the ideal primary tube size for a basically stock (just tuned) 8.1 in a truck that is used for work and also fun?
 
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