RV6 wrote:

TKOPerformance wrote:

Reading his symptoms now I'd say not.  That's a cardinal no-no. 

Me thinks you're reading between the lines about my engines symptoms. Basically the lifters bleed down overnight and during the first second or two after start the valve train rattles. It may run rough if it has sat in the 30's for a couple of days on first start. Almost like a valve could be sticking. Nothing leads me to believe there is any problem with the cam or the lifters.
Manifold vacuum is steady at idle and throughout the engine operating range. She's has great low end torque for everyday fun driving, even up here at 8500'. She runs out of breath at 5000-5500 rpm; a result of cam choice. 
An oil change is due in a couple of days as I topped off the crankcase with about 1/2 quart of ATF and she deserves a fresh oil change for the Bash trip.
 

Pour the whole quart in and........"let'er slosh"!
6s6
 

rpm wrote:

I think we have a higher chance of Colorado to continue to get more snow than mechanical issues. Do I need to carry chains???

No more snow. The high country is warming up and now the rivers are getting full. Pontoons.
 

I must have read a dozen books on engine building where they said a cam and lifters were a set and if half that set is new the other half must also be new. 

That said, this prompted me to research the issue more thoroughly.  I couldn't find a single post, article, etc. where anyone said running new lifters on an old cam caused a problem other than noise (ticking) that couldn't be adjusted out.  On the other hand, many, many posts were from guys who had done it successfully.  Probably the most telling piece of information is that if you consider that if a lifter goes bad under warranty they would simply replace the offending lifter.  Now, of course they are going to go cheap on warranty repairs, BUT they also don't want that vehicle coming back a second time, so...

I did read a couple of things to be cautious of though: First, the new lifters and old cam combo should be treated just like a new cam lifter set.  Break in lube and run the cam in for 15-20 minutes at 2,000RPM.  Second, if the old cam is damaged new lifters obviously won't fix it, and this could lead to a wiped cam lobe(s), turning an annoyance into a serious problem.  Third, if the cam is aggressive and the springs are stiff the chance for trouble is greatly magnified.  When running the cam in again it may be necessary to reduce spring pressure on break in if that is advised on a fresh cam/lifters by the manufacturer. 

My take away is that I still wouldn't do it, but then again I'm struggling to remember what I own that actually still has a flat tappet cam in it other than my 289.  If something went bad in that valvetrain I'd just swap to a roller and be done with it.  If the engine was out and being rebuilt there would be no reason not to just install new/new.  In a repair situation it seems acceptable practice with fairly low risk so long as the engine is stockish. 

Pump your brakes a second, Diesel oils now also have reduced ZDDP.  This started some years back.  I'm not saying don't run the Rotella, its great oil, but you should still add some ZDDP (I just use STP from the local NAPA) to account for its lower than ideal ZDDP content in its current formulation. 

Old engines like dino oil because of the way they are built. If you were to rebuild your engine to new specs (clearances, ring pack, piston fit, wall finish, roller lifters and so on) then the new spec oils wouldn't be a problem. I get my Valvoline VR-1 from our local Carquest for $42 a six pack ($7 a quart) which is fine with me. I see it on Amazon for as low as $36 a six pack but I'll put the $6 more back in to our local economy.

I'm glad to hear that things are quieter under your hood!

Lots of advice above.  For what it is worth, Ford Motor Company, in one of the early Tecnical Service Bulletins, called the cold engine lifter noise, "morning sickness" and said "no worries" or something to that effect.  These old small blocks will run a long time at less than perfect condition.  Us old gearheads all too often spend hundreds of dollars on ten dollar problems.  May be best to wait for more symptoms before dropping a big dime on the " morning sickness".
Best,
Al

Yeah, but give it some time and there'll be a 5 paragraph IMHO post disputing Al's advice....

Bullet Bob wrote:

JKB, what you said!

 
LOL.  So true!

Love to see ya again "big Al"!!
Hitch a ride wid some of dem Texas coyboys and meet me in Mich.
6sally6