So I stripped them bare today and taking them tommorrow to get checked for cracking. If all is good I'm making the swap from the "990"s. They'll be cut for 2.19/1.88 valves and some bowl blending. I have closed chamber pistons in the 439 now, and I'm figuring the boost in compression will help the XE284 cam. I suppose the 1/4 mile will tell the tale! Tony A. :D

Originally posted by chevywidow:
I suppose the 1/4 mile will tell the tale! Tony A. :D What's it run presently? It will be interesting to see the comparison!

Rod

Last year with the GMPP Roval's it went 11.988@112.48. Previous to that with the "990"s, it went 12.15@111.78. New valve springs will definately help!