alignment question

[68jimmy]

Last weekend I swapped the front springs in my 68 gmc 3/4 ton for a set of 1/2 ton from a 70 chevy. In addition I replaced the upper ball joints as the others were trashed. I'm sure that the lowers and tie rod ends are in need of replacing as well, but funds are a bit low... I took the truck to the local pep-boys shop perform an alignment, they called later saying their specs didn't go back that far. I told them to use the specs from a 70 as they should be the same. Well after driving it home it seems to pull more to the right than before... But it's weird, some stretchs of road it tracks fine but mostly it wants to go right.

Here are the numbers from the receipt:

Specs
Caster: Min=-0.2, Max=0.8
Camber: Min=-0.3, Max=0.7
Toe: Min=0.13, Max=0.25

Left Front
Caster Before=1.9, After=1.9
Camber Before=0.6, After=0.4
Toe Before=-0.15, After=0.15

Right Front
Caster Before=2.1, After=2.1
Camber Before=0.5, After=0.6
Toe Before=-0.25, After=0.15

Could the caster be the culprit? And will replacing the lowers and tie rod end correct the caster? Another concern is at the top of the page of the receipt they have a 1979 chevy c20 for the specs... Are the alignment specs the same? Should I take it back and have them use the specs from a 1970?

Thanks!

[GMCPaul]

69-70 C1500&C2500
Camber= .25degree + or- .25 degree
so Camber = 0degree thru +.50degree
Caster= 0degree + or - .25degree so Caster= -.25 thru +.25 degree
Toe-In= 1/8"-1/4"
GMCPaul