I have a set of 990 heads being redone off of my 454 mag and the machine shops needs the installed height of the valve springs. I could also use the recommended seat pressure and the recommended psi of the spring when open. I need this asap! help please.

I can you tell you the stock cam specs and they might be able to work off that.

.510/.510 , 220/220, 115 lobe separation.

about 1.900 should be fine, thats what mild comp cams springs are designed to run at, spring pressure going to be with spring choice at that height...Rob