[MarkS57]

I was able to get my hands on a bunch of NOS TRW VL49 lifters for close to nothing. These were a go to stock HFT years ago. They are in the lighter blue colored boxes, not the darker boxes. There are 2 different types within the lot, see pic. Most are like the one on the left, looks familiar. Does anyone know how to decipher what I believe to be date codes shown on the box ends? Thanks!

[ponyakr]

I've read that the lifters made by Delphi have a hardened foot. You can tell that the lifter on the left has this foot, by the low groove.

Have read that Delphi use to provide lifters for lots of GM factory engines.

[Joe's Garage]

Those 'date' codes are on the inner flaps of the box.

There will be be 2-digit 'date code' on one flap (see the 1st pic below) that indicates the year. This box was printed in 1990.

Then on a flap from the opposite end of the box, there will be two numbers, one for the month and one for the day. Sometimes there will only be the month and no date. See the 2nd pic below - this box was printed on 8 - 10 (August 10th).

The 3rd pic is of 2nd box, also from 1990, that does not have a 'day code' but does have a 'month code' printed (again 8 for August).

The 4th pic is of a late 90s vintage Sealed Power box. It is coded to show that the box was printed in 09 of 98.

I've never seen a deciphering key for the codes on the outside of the box, although the gang-stamped digits probably do decode to something.

I believe that TRW was a reseller and not a manufacturer, so whatever dates you can decode would most likely indicate when the lifters were packaged and labeled for TRW and possibly decode to indicate who the actual manufacturer that made them for TRW was.

Although, as ponyakr has pointed out, the physical characteristics of the lifters are the best indicators of who the manufacturer is / was.

Hope this helps.

[MarkS57]

Originally Posted by Joe's Garage

Those 'date' codes are on the inner flaps of the box.

There will be be 2-digit 'date code' on one flap (see the 1st pic below) that indicates the year. This box was printed in 1990.

Then on a flap from the opposite end of the box, there will be two numbers, one for the month and one for the day. Sometimes there will only be the month and no date. See the 2nd pic below - this box was printed on 8 - 10 (August 10th).

The 3rd pic is of 2nd box, also from 1990, that does not have a 'day code' but does have a 'month code' printed (again 8 for August).

The 4th pic is of a late 90s vintage Sealed Power box. It is coded to show that the box was printed in 09 of 98.

I've never seen a deciphering key for the codes on the outside of the box, although the gang-stamped digits probably do decode to something.

I believe that TRW was a reseller and not a manufacturer, so whatever dates you can decode would most likely indicate when the lifters were packaged and labeled for TRW and possibly decode to indicate who the actual manufacturer that made them for TRW was.

Although, as ponyakr has pointed out, the physical characteristics of the lifters are the best indicators of who the manufacturer is / was.

Hope this helps.

Originally Posted by ponyakr

I've read that the lifters made by Delphi have a hardened foot. You can tell that the lifter on the left has this foot, by the low groove.

Have read that Delphi use to provide lifters for lots of GM factory engines.

Thanks guys, yeah, Delphi seems to be the manufacturer of the hardened foot lifters & very much appreciated date code info. I'll check the boxes when I get home from work.

Each box has instructions for installation, for both stock & hi rev types. I'll have to see if they recommend removing valve springs on the hi rev types.

[MarkS57]

Date codes put the lifters as on the left at 1987 & 1988; on the right, 1983. The instructions make no mention of lightening the valve spring load at break in. The anti pump up lifter instructions suggest adjusting the lifters while the engine is running.

[NeighborsComplaint]

Can't help with date codes but left is a standard Mellings JB-951 lifter and right is a Sealed Power/SpeedPro HT-951R High Rev lifter.

Left: https://www.summitracing.com/parts/m...+5ba288b21bba3

Right: https://www.summitracing.com/parts/slp-ht-951r

[MarkS57]

Thanks to all who replied.

I guess my question would be if, as these things are 33 & 37 years old, might they be higher quality than what is out there now in the market?

I recall using these VL49's on 60's - early 70's Pontiac V8's that came with the 40 lb oil pump. Those engines always seems to have lifter tap issues. A TRW cam & the VL49's quieted those engines right down and would stay that way.

Somewhere I read that it was due to soft metals of the OE stuff; the HP engines with the 55-60 lb pumps never seemed to have the lifter tap though.

[Joe's Garage]

I'd use them. Steel doesn't go bad sitting in a box on a shelf unless it gets rusty, and yours look to be in great condition.

I can't recall anyone having 'flat lobes' or 'cam failures' in the 1980s unless they did something else wrong resulting in a catastrophic failure of some kind.

Our hypothesis would be that parts that were made in the 70s, 80s and even very early 90s actually had QUALITY CONTROL. And they were mostly MADE IN USA.

Disassemble them - one at a time, so you don't get any parts mixed up - and THOROUGHLY clean every part with solvent or gasoline or brake cleaner to remove all the factory assembly lube - it's probably turned to glue by now. Reassemble carefully and correctly, re-oiling the pieces as you assemble.

Then pump them up in the can of 30W (old school) until the bubbles stop coming out and you're ready to use them. For stock-ish applications, obviously.

We have several sets of 1990-dated box VL49s for future refreshes - thus the box pics. We will have no qualms about using them.

Good luck!

[Tom Vaught]

I have 3 sets of the VL-49 Hydraulic Lifters that I do not plan on getting rid of as you mentioned they are very high quality OEM type parts.

Tom V.

[daduck]

I found some surplus lifters and pulled the trigger @ $49.00 for a set of 16 shipped to my door.
Out of the box ......Nice cross hatch pattern on the face.
Took the first one apart and it was clean and still had an oil coating on the internal parts.
The label on the 8 pack: SEALED POWER HT951/VL49 VALVE LIFTERS.

Deal or no Deal????