Porterbuilt control arm help

[Tinsmith]

I purchased some upper and lower control arms, Was putting everything back together on the front end but the upper control arms ended up hitting the stock upper crossmember that they bolt to. They are not able to fully seat aganist the bracket, there is those 1/2 thick spacers from the factory arms but that is still not enough. if I make a 1'' thick spacer will that effect the caster,camber? if it comes down to it I could shave some metal off the bracket, but I just had them powdercoated will post some pictures but need to go get a connecter for the phone to upload pictures. also the holes on the crossshafts on the porterbuilt arms seems a little large for the factory studs, is there a difference for the different years 67-72 73-87 cause i upgraded to 73-87 steering.
thanks in advance for any help