need help w/ cam and cylinder swap!!

The Comp recommend springs are 995 for that cam, and the spring rate is 402 lbs per inch, which is pretty stiff. They would have an almost identical spring pressure, 135 lbs, for a closed valve at 1.650" installed height, as the 125 lbs cited above. So the closed spring pressure of the springs you are getting is very close, maybe a bit lower. I suspect the Aero spring are not as high a spring rate as the Comp 995's so the open pressure will be lower too. Seems like you friend is a mite uninformed on that point......

You WILL need to be very careful in your break-in procedure, and make sure you use the proper cam break in lube on the lobes and lifters. Read up several articles on proper cam break in, and follow that religiously. The cam is somewhat agressive on the lobe ramps.

The one thing for the Aero springs is that they say up to .509" lift. Your cam will be up to .491" lift. If the Aero springs actually bind at .509" then you have a problem; you need about .060" minimum margin between coil bind and max lift; you would have only .020" margin.

Now what I do not know is if the advertised max lift for the Aero springs of .509" accounts for some extra motion above that. In other words, do they mean the coil bind is actually .569" or more? I would by all means call them for a clarification, and THEN also check when you get them to see how far the valve can move before coil bind.