OEM or aftermarket are probably equally reliable. It's the labour involved for replacement that makes it non cost effective for the most part.

1) there are third part CAM providers that provide CAMs with reduced base circles , this reduces excessive drive train tension.

2) there has been a problem with rebuilt short blocks and "reman engines" in that the heads are planed to straighten them out.....but nothing is done to account for the shorter drive train distance. if you plane your heads you need shorter pushrods

3) while 5W40 is acceptable year round....if you are running a stock truck with DPF in tact,, the best option is to run 5W40 during the coldest part of the year and a higher weight such as 10W40 or even 15W40 during non winter times of the year. this helps prevent CAM damage caused by highly diluted oil . 10W40 and 15W40 has a longer way to go before loosing lube value than 5W40 as the oil gets thinned out with fuel.

I ran 15-40wt only in my 6.4 and changed it at 5K intervals.

I did many blackstone OA's. My fuel dilution was non existant for the most part. No idleing and no in town stop and go driving was the rule. That doesn't mean I didn't but that was not the primary use,

Yes, Plugged in. Our temps here near DC in the winter average around 30F in the winter.

I have a commuter car for the cold days.

[QUOTE=koboss1;8883719]i ordered a new crate engine from a guy in the states for my truck, he has a friend at the truck plant that sells the surplus engines from when they stopped putting them in the superdutys. these are still covered up sitting on the crate from navistar and i got it for $6800. complete drop in and go..

anyway what i was wondering is if i should sell the old engine or keep it for parts? its still running strong what would one of these be worth..

thanks
koboss[/QUOTE

are you still able to get ahold of these engines?

Engine life
 

the oil u use makes a big difference. Ams oil works very well. I have a 96 351w with 313000 miles on it I just put a new timing chain set on it . It had 1/2inch ware on it.also keeping the engine cool is the answer 😎. I treated my engine with the original slick 50. Metal treatment. I am going to try to get 1 million miles out of this engine.

With the 6.4 frequent oil changes are recommended due to the upper wear of the rocker arms. I always ran 5K oil changes and used Motorcraft oil.

we used Castrol oil in all the new engines we built. I would also recommend 3000 mile oil changes. And maybe lucas oil additives. That will have the ability for oil to be in the top end on start up.