I have the pac 1518 kit which has the springs, seats, locks, and seals. I got them off of a dyno time only motor with l92 heads. They are going on my 4.8 with 799 heads. I pulled the stock spring and seat/seal. I went to install new seat and seal but the seal is really loose... Like tighter on valve then on the boss it goes over. I tried to put the springs on stock seats but the ID of the 1518 is bigger and spring has a lot of movement on there... What should I be doing?

 

Is it possible that the seals are a little expanded from already being installed and removed from another head? (Do L92's and 799's use the same seal? Not sure...) I'd probably get new seals to be on the safe side...

 

If they are a one piece seat and seal then the spring force will hold it down no problem. Mine were two piece so the seals fit pretty tight on the boss.

I would imagine with a one piece as long as it seals well on the valve then the spring will hold the seat/seal down and you should be good to go.

Some others may chime in though...

 

I'm pretty sure that the PAC 1518's require the separate seat/seal for clearance, but I'm not 100% sure about that one...

 

I got it figured out now guys thanks for the input. The id of the seals I have are oversize. Although they don't appear to be used. Got new seals. I could use the stock seat but the spring has a lot of play. The id of the 1518 is a bit more then stock

 

Ahhh, I'll bet that the seals that you had were intended for aftermarket bronze valve guides