Finally got my 406 installed and running last night. Specs on the motor are:

400, .030 over with splayed mains
New rotating assembly; set up for 9.5:1 with 65cc heads
AFR 195 Heads
Crower CAms retro roller 00468
7104 RPM Performer intake
Quadrajet
2400-2600 stall

Got her fired up, set the timing at about 15-16 degrees initial and let it run about15-20 minutes. It sounded great - like it would just tear your face off. In a good way. Then it happened: a small pop-tick tick tick tick on the passenger side.

Shut it down, checked for anything external like a loose or burned plug wire - nothing.

Pulled the valve covers, and the #2 exhaust lifter was a little loose; # 6 exhaust was also, but slightly less, loose. Took the rockers off, inspected pushrods, all straight and true, no blockage in the center passages. Couldn't see much looking into the lifters from above, but other lifters had oil pooled in the cup of the lifter, except for the #2 exhaust - empty. Shot a little solvent into it, it drained fairly quickly, so I can tell it will at least circulate oil.

I think my options are:
- Check rocker arm travel as an indicator of cam lift before I pull the intake - hopefully the lift is consistant from exhaust lifte to exhaust lifter - if no problems, assume cam is good.
- Pull intake and lifters, inspect and clean as much as possible - maybe blow out oil passages feeding the lifters with compressed air

Anything else I need to look at?

 

OK, hate to admit my own mistake, but this could be a lot worse, and maybe someone will use my experience.... pulled intake, inspected cam (as much as possible through the bores and the drain holes in the valley - all lobes were smooth. Found a slight scoring inside the lifter cup - just next to where the pushrod should seat.

Looks like when I adjusted the valves, I did not have the pushrod fully seated - after startup, the pop I heard was probably the pushrod seating.

I could have sworn I looked at each pushrod twice before installing the intake - but I guess maybe not closely enough.

Boneheaded mistake, but lesson learned: Take my time, check twice, and when I think I'm good, check a third time anyway.

Intake goes back on either tonight or tomorrow AM - should be driving this weekend (weather permitting).

 

It can happen with the intake on
Good luck and make sure you don't have the rockers hitting the valve spring or the spring binding.
Keep her revving

 

If you change the cam,you should go with hydraulic roller,dont have to ever worry that you will wipe cam. with flat tappet cam you always have to run the RIGHT oil ,if you make a mistake and use the wrong oil ,its possible you will wipe cam out.Also if your engine was new ,you have to brake in the cam with break in oil.

 

Thanks, It actually is a hydraulic roller - Crower 00468 - I was worried that a lifter had failed and absolute worst case, possible damaged the cam (thankfully, that didn't happen).

Looks like all is well now - the lifter is replaced, am going to fire it back up soon as I am done watching the Ohio State game.