L86 to L8T in '19 Yukon XL Denali

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L8T BURB

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Mounts are in and trans is mated. Just replaced the passenger motor mount so I still have the one parts store special on the driver side, but I didn't feel like swapping it out since it is fully installed. Didn't realize the harmonic balancer was a one time use TTY bolt, so have another one on the way that should be here tomorrow. Should be able to wrap this up after work by the end of the week and have it on the road. I've gotta work around the weather as I'm working out of a smaller 2 car garage that requires the door to be open when working on it.

My thoughts behind this swap is a more reliable family daily that can tow. MPG will be what it is, be it better or worse.

@L8T BURB - I reached out a bit when I first started and got notta for response, but I'll try again. Push come to shove I've got a basic L8T file to get me started.
@chevman88 He usually lets calls go to voicemail if it's a number he doesn't recognize. Be sure to leave a detailed message and call back number. He is usually quite prompt in communicating.
 
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chevman88

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He didn’t bolt up any old GM block. He wouldn’t be needing a “tune” file with a 1970ish BBC bolted up!
This is true, the bell housing bolt pattern is slightly different from gen4 and prior. Instead of the 6-7 bolts (2 on each side surrounding the dowels, 2 further up on the angled portion and maybe one at top center) there are now 8 bolts (2 from oil pan, 2 on each side surrounding dowels, 1 slightly off top center and one driver side on the angled portion). I'm sure there's a way to adapt them to make it work with older style bolt patterns, but it's not 1 for 1. I'll upload a picture of the newer one when I get home and can take a picture of the back of the L86. The HPFP drive prevents the top center bolt, so it's now slightly offset.
 

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