Cm870 upgrades

[Rawze]

(01-02-2017 )Rig Wrench Wrote:  I'm in the process of overhaulin a CM870 in a 379 Pete 565hp. Anyone ave any recommendations for upgrades while I'm in there? I know it needs a new cac, any recommendations on a better than factory replacement? Not lookin for the most durable, but the best flowing/most efficient. Any other recommendations are welcome. Hope to get another 850k mi out of it.
Thanks

* Counter-bore and raise liner height to 0.014" or 0.015".

* Have the head hand torqued to 300-ft lbs, and let it sit overnight so that the gasket will crush properly. Torque it a second time the next day, then do the 90-degree final torque on the bolts after that. Most shops will not bother to let it sit overnight, then re-torque because they are in too much of a hurry.

For the CM870 ..

* Make sure you look up your engine serial number and find the exact timing code. CM870's have timing codes based on engine individual ser# and it does not always match the engine cover sticker. they also have ECM programs to match this, so use the original program for it and have it custom tuned instead of replacing it with a different hp one. - Very common mistake people do on them.

* A better intake manifold for the CM870 has slight improvements. Exhaust manifolds for them on the other hand, are a waste of time/money and you will see no measurable gains from them. Not even from the high performance ones.