ok so i just bought these springs for my 318 heads and after i put all the comp cam springs on i noticed that the stock springs i took off arnt all the same hieght.
so what i was wondering is are the #901 springs different hieghts as well or are they all the same hieght????

Once they are installed the distance between the retainer and seat will establish the height. Your old springs may be worn out and took a set at different heights.

the 8 shorter springs would have had the rotators on the top to let the exhast valve spin as it opened/closed

if you installed them,I would think they would work fine..but it will make the retainer to valve guide clearance less

what you need to do is go back and swap all the rotators out for 8 more intake retainers for a total of 16 intake retainers

this will make all the springs same height and give the best clerance on the valve guides

let me know if you need 8 intake retainers,I have a box full of extras...you can have 8 of them

Leave the rotators off Period. No ifs, ands, or buts about it. Leaving the rotators on will only shorten the installed height of the valves springs along with guide to retainer clearance do to the shortened installed valve spring height. Fine with a stock low cam but any performance grind and you can have trouble with a capital T. Just get 8 regular retainers and use in their place. Not a big deal but it could be if you use the rotators which can very easily cause coil bind. This is what can happen with 484 lift using the rotators on other wise correct springs. Not picured is the cylinder wall that needed sleeving, cam shaft, head, and a couple of rods.

Ohh dang I don't want that to happen to my enigine ha
I'm gonna just swap out those retainers for the intake ones

And the heads I took took them off were rebuilt and had everything new so the springs I took off had to have to come like that cause iv only had them for about 2 weeks and they have yet to be used on a running engine

yes,stock spring on the exhast valev with a rotator is a little shorter than a stock intake spring

just use the intake retainers on the exasht valve with the comp 901-16 springs

good to go then