:banghead::banghead:I have a 426 world block hemi with indy legend heads,i am on my 3rd set of lifters. I am not sure what make of lifters were in it when I got the motor,but they had a circular snap ring{C clip type},the motor started running rich one day and I could hear in the exhast something wasn't right.When I took off the intake and vally plate I found a couple lifters had lost the retaing clips and one lifter tappet had been pounded n broken. So... I ordered a new set of comp cam hydraulic flat tappet lifters and installed them{these have a stamped steel retainer plate in them}, I adjusted my valves as you normally would do, and I noticed I had to adjust the rockers quiet a bit more turns then the adjustment of the lifters I took out. Seemed to me it put a lot more angle on the push rods and rockers. Well I started it up and it was noisy as hell,so, I tore it apart again and compared the new lifters to the ones I took out,wich I realize now I should have done in the first place. Turns out the tappet height in the lifter was not the same, infact it was .080 shorter then what I took out. oh and one or two of the retainers had came off the lifter again! So I ordered a set of mopar performance lifters for a hemi with the tappet to bottom of lifter height of .588. I installed them adjusted the rockers and every thing was fine for about 3000 miles. I just installed a tti 3 inch exhaust and noticed a little tick coming from the drivers side exhaust and that it was running really rich again. So I decided to take off the intake again and check the lifters and sure enough 3 of the tappet spring retaining clips had come off! After close examination I found that my pushrods that are 7/16 dia with 3/8 tips are to big for the lifter cups and ride on the upper edge of the cup. So im having a new set made with 5/16 tips so they set all the way in the lifter tappet cups. In the mean time I order a new set of lifters from hughes engines because on their website it show that their lifters have the bottom of lifter to bottom of tappet cup height or.588 that I need and they have the heavy duty retaining clip in them. So I get them today and check them with my verina calipers and they are not the .588 that they said they were going to send me , in fact they have the same deminsions as the comp cam ones that were wrong before! The tappet is .080 shorter. So should I return these lifters and try to find the correct height ones or would I be better off adding .080 to my new pushrods? Is ther a difference between hemi and rb motor lifters..or am I completely missing something? I do not know the cam spec s other then its a hydraulic cam ,I do belive the guy who sold me the car may have had multiple hemis and took the heads of one and put them on mine not noticeing the difference in pushrods, but I really need advice because while im knowledgeable on 440's, I have a lot to learn about hemis. THANKS IN ADVANCE FOR ANY HELP YOU CAN GIVE ME!:banghead::banghead::banghead: