[mudbird]

Hello all, I am in the process of changing the cam in my street/ strip firebird. I had a comp xe 274 in the motor before (461 eagle stroker 400 block) and I happened to get an unused HO HC-02 from ace's garage sale.

The old combo always had some valve clatter on the #1 ex and #6 intake but it did not get any worse after 100 runs and about 6000 street miles. When adjusting the valves I could get the noise to get better but I could see the speed of the pushrod rotating slow down when I tightened it that much. So I set them at 1/4 turn and lived with the noise.
The lobes actually looked pretty good (lifters too) when I removed the old cam a few weeks ago.

Thanks to this board and its members willing to share their knowledge I know a little more today than when I had my heads done by a reputable pontiac builder here in town. The heads where done in 1999 and both received hard seats and guides as they where in pretty ruff shape. I got them from a junkyard, they are casting #48 that I think are from a 350 because the chambers measured 68cc. I bought the valves from butler, I believe they are ferrea's but all the receipt say's is item #60 high performance plus valves standard D-port. They have the comp 995 springs, 10 degree chrome retainers and 11/32 locks. I bought all these parts from Butler myself in 1999 and brought them to the guy.

I am checking everything this time and I noticed the if I put a straight edge on the valve tips (heads on motor and motor in car) that I can slide about .015 under some of the valve stem tops and installed height does seem to be about 1.64 to 1.68. I do not have the right mic for springs just a rough guess with a reg mic.


I run the scorpion rockers (1.5's) and the arp studs and have always adjusted the valves on the motors in my car as I have run a few aftermarket cam in the past.


Everything is looking good, pushrods, rockers ect I want to know if this is a problem.

I will be checking the pressures and clearance to the guides/pc seal to.
I suppose the after a valve grind they might be a little different but I was wondering is these heights normal when replacing seat and guides ?

I would think you could put them where you want.... but I am not a valvegrinder and they are really not that different to me .008 to .012

Thanks