Not sure what this means:
But the lifters in it are hydraulic, so is stock hydraulic or mechanical?
Is what "stock or mechanical"?
I seriously doubt you could find mechanical lifters for a Chevy 350 engine.
And i just want to replace lifters, not the cam and all, also the rock arms arnt adjustable, theyre from jegs and have 1.6 on them, effect anything?
While renewing only the lifters - on an existing cam - isn't recommended, it can be done. But NEVER attempt to do the opposite (i.e. install a new cam under existing lifters).
Since it appears you are determined to replace just the lifters (and leave the existing cam in place) keep one important thing in mind:
you will have to do a proper break in procedure - just as if you were also replacing the cam/lifter set.
If you simply pull the old lifters, drop a new set in and drive away - they will be toast in no time. Not only will the lifters be ruined, but the cam and pushrods will be destroyed as well. Trust me I know, because I did that once. Never again:
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
Any time a new set of lifters is coupled with a cam (new or old) they need to be mated to the cam lobes.
The face of a cam lobe is much harder than the base (foot) of a lifter and it is ground at an angle. That angle causes the lifter to rotate slightly each time the lobe pushes up on the foot of the lifter.
Also, the foot of the lifter is not perfectly flat, instead it is slightly convex. The convex shape of the lifter foot combined with the angled profile of the cam lobe is what causes this rotation. The rotation of the lifter keeps the highly loaded interface between the lifter and cam lubricated and cooled so as to not cause excessive wear during operation.
The break in procedure is when the relationship between the lobe and foot is developed. It takes about 20 minutes. After that the lifter is forever "married" to the cam lobe.
I won't get into the break-in process right now. It is available everywhere.
But before you even buy new lifters (BTW - I get good performance and long life out of either Sealed Power or Melling), you might consider freeing up your sticky lifter.
It isn't hard at all. Pull the lifter you think is not fully stroking - just that one - and put it on the bench. Actually this is best done in a clean uncluttered environment, like at the kitchen table. Refer to the images at the bottom:
Before beginning work, have a clean well lit work area prepared.
Use clean lint free rags or paper towels. To clean, use carb spray, acetone or lacquer thinner.
To disassemble a lifter, depress the lifter cup using a wooden dowel or a pushrod. This allows the retainer clip to be easily removed from the groove in the lifter body. Use a pick and lift one side out of the groove and the clip will come out.
Warning Be careful to not accidentally shoot the clip across the shop.
Once the clip is out, the pushrod cup and metering disc can be removed, followed by the inner plunger assembly. The plunger can be stubborn, tapping the open end against a cloth-covered wood block will usually bring the plunger to the top of the body allowing it to be coaxed out the rest of the way.
On the bottom of the plunger you will see a cup and a stiff spring. Remove the spring and set it aside. Inside the cup is a small spring and check ball (left). Some designs use a small disc instead of a ball, however check "ball" will be used herein. The cup is a press-fit onto the plunger, it snaps off and back on. With a lifter that has collapsed or is noisy, often all that has happened is the cup assembly isn't fully seated into the recess on the bottom of the plunger, or a speck of dirt has lodged between the check ball and seat.
Remove the cup using a pick and see that the tiny spring isn't bent, kinked or missing, and that the check ball is there and is smooth and shiny, and that the seat on the plunger that the ball seals doesn't have any ridges, burrs, or imperfections that would prevent the ball from seating properly.
Lifter reassembly
The plunger gets the cup containing the tiny spring and check ball (no lint!) snapped back into place. Be sure it's seated squarely on the bottom of the plunger. It doesn't take a lot of force, just be sure it's on all the way and sits square on the plunger.
Lightly lube the plunger using motor oil, put the stiff spring over the check ball cup on the bottom of the plunger, then insert the plunger assembly into the lifter body (again, no lint). Work the plunger up and down a few times (it'll take a minute to bleed the air from it) to verify it works smoothly and doesn't hang up or have any gritty feeling.
Next replace the metering disc and then the pushrod cup. Using a wooden dowel or a pushrod, depress the pushrod cup and reinstall the retainer clip. Again- be careful to not launch the clip into orbit.
At this point the lifter can be depressed and should return smoothly to being fully extended.
Personally, at this point I submerge the lifter in a container of clean oil and depress the plunger a couple of times to prelube the guts.
You must be registered for see images attach
You must be registered for see images attach