axle perch question

I'm converting the rear axle of my 51 chevy pickup over to an 8.8 while im installing a tci rear leaf spring kit. The kit came with new perches that are for a 3" axle. My 8.8 is 3.25. Am i safe to mark the perches for the new diameter and then open them up a bit so that sit down flush? How precise do i need to be. Is a cardboard disc cut out to mark 3.25 with the calibrated eyeball, then open up with a flap wheel, good enough? Or would i better off having a machinist freind open them up more precisely?

Im sure that i'm probably overthinking this! ...just dont want to have problems with my rear end walking down the road sideways.

 

I don't see a problem with that.

 

mark them , then grind them to fit

 

Remember your supplied U bolts and lower spring plate will not work on 3 1/4 tubes they are 3 inch.

 

That's what I did on my 8.8" swap. Just ground them out to fit, and welded them on. I also used the 8.8" donor plates and U bolts.