Forgot to mark where the pushrods go when I took them apart. Im now putting it back together. there is 2 different lengths of rods which order do they belong?

put the engine on tdc compression stroke and place the 2 rods of different lengths in position
one will be too short and one will be too long
once you have the rods in place they alternate in length

Your push rods are different lengths. The intake push rods are the shorter ones and are marked with yellow paint. The exhaust push rods are marked with green paint. Double-check to make absolutely certain that you have them all in the correct position. (failure to do so will cause IMMEDIATE severe engine damage when the starter is cranked.)

Other than that, it is common for the lifters to leak down when the engine has been disassembled. I have even had several that made it very hard to start and "clattered" for like 5 minutes after starting the engine. It will be OK when the lifters pump back up.

push rods are the same length on a 3.8 motor but not on a 3.3 or a 3.1 motor i can`t quite remember right now.that`s why techs put the pushrods in a peice of cardboard marked which cylinder they have come from.

The intake pushrods and exhaust pushrods are different lengths. To distinguish the different pushrods, paint has been used, although this paint may be hard to identify after prolonged use. The intake pushrods are color-coded orange and are 6 in. (152mm) long. The exhaust pushrods are color-coded blue and are 63/8in. (162mm) long.

Here is a picture of the cylinder marking:

If the engine oil was full of antifreeze when the intake gasket went bad, then there is a good chance that there may be some cam and/or lifter damage. A more likely cause of your problem would be that the push rods got mixed up when you put it back together. The intake and exhaust rods are different lengths. If this is the case, and you have turned the engine over, there is a good chance that you now also have a bent pushrod and intake valve. The exhaust pushrod is the longer one and if you mix them up, the piston will contact the intake valve because it will not be able to close due to the longer pushrod. This will bend or break the pushrod and bend the valve stem.

intate and exhaust push rods are the same size and part numbrer, so nothing will happen, they are both
6.9" overall length

The pushrods are all the same. If you're putting new ones in, they make no difference. If you are putting the old ones in, they HAVE to go back where they came from, as they wear uniquely to the lifters and rockers. Hopefully you kept them in the right order when you took them apart. The other important point is if you're putting old ones in, make sure they're not bent.

ok i understand what you are saying now.

the euro sport is the same as the lumina base just with a body kit, stiffer suspension, and dual exhaust.

but on the 3.1 engine the pushrods are all the same length, but depending on the stroke each cylinder is on the pushrod may be in a different position.

you are assuming that every pushrod should be in the rest state. that is not true. if the cylinder you are installing the pushrod for is on the intake stroke when you install the intake valve pushrod and tighten the rocker arm nut the valve will procede to open like it should be open for the intake stroke.

this is normal and its nothing wrong with it.

No, it's fairly easy, just remove the valve cover, unbolt the rocker arms, remove pushrods. Make sure you have correct parts and compare length of new ones to old ones. Too long of a pushrod and you could have major damage. Slide pushrods into lifters, you can look down through the head and see the lifter. You can also feel when the rod is in the lifter correctly. Install rockers in reverse trying to put back in exact location. I recommend torqing these, you'll have to find the spec. You could spin the engine with coil unhooked so it won't fire before you put the valvecover back on to make sure they're all moving the same. Install valve cover, etc, your done.

the only thing i can think of is
1. did you check the journal clearance to the main and rod caps? if this isnt within specs could be too tight.
2. did you put the rod caps and main berring caps on the same way you took them off....ie did you mark every thing 1 for #1 2 for #2 ect. if you installed the berring caps the oppsite way or didnt keep them in order some thing could be out of round causing tightness.
3. the same goes for pistons.......the mark should be pointing front for all. (ch approiate engine rebuild for info)
i would recomend trying to remove all spark plugs and try to turn the engine by hand( DO NOT TURN IT BACKWARDS>see which way the starter turns the motor) feel how it turns. if its hard then easy some thing is out of round poss installed wrong. personally id take down the pan and check the install. also take valve covers off ck the clearence of rocker arms. check your pushrods valve motion ect. you might also might want to break it down before you do some expensive damage.
tip.....if you didnt mark the rods and main berring caps and might have put them together incorrectly, remove the berrings and look at the honing marks. with patience and a good light you can see if they are lined up(cap and block for mains and cap and rod for connecting rods.) ie the cross marks line up.
good luck