LT4/8L90 into 1966 C10

[hddoktr5]

LT4/8L90 into 1966 C10
Howdy folks ! My second visit, no response on the first so thanks in advance for your patience!
I bought a connect and cruise package that has engine , trans, ECU
and TCM . (Think the acronyms are correct!) Anyone out there done
that ? Looking for guidance on cutting the floor and or firewall for the
8 speed , Headers ? Any other issues you care to share? Thanks much
Any help would be appreciated

[TotallyHucked]

Unfortunately this place is fairly dead. You'll likely have better chances with advice or finding others that have done that on one of the many C10 Facebook pages.

[rrlanejr]

I put an LT4 and 8L90 in my 85 gmc. Being a connect and cruise im guessing you will be very happy with the tune and trans tune. I have a seperate PSI conversion harness with a 2018 Z06 computer.

You will have to cut the trans tunnel, its a much larger transmission. Depending on how low you go, you may have to allow for the driveshaft. I don't think you should need to push back the firewall.

I mentioned the tune because my engine and trans tune is still not where I want it. Its really close but the GM tune should work great.

[nekkidhillbilly]

67-72gmtrucks is the best full size chevy forum