how much differance on center to center(or on any of it) can a alum hemi rod have (brooks 88)
thanks

if your comparing the length of a set of rods, + or - .001 would be normal. you shouldn't see much variation in length.

ralph here(toplescuda) on differnt comp i measured my rods with a dial caliper 2 rods were shorter center to center one was 19 thou shorter think the other 12 thou

Sounds like those rods are ready for the scrap yard, they have been stretched. I wouldnt use them in any engine what so ever.

That would make me very nervous. 2 obvious reasons:
1. poor quality control (they should never go out the door like that)
2. the long ones are stretched, and should be trashed
Unfortunately, without an original length measurement, for all we know all of them are stretched.

my thinking is at some time 2 rods got kicked out and were replaced i had all 8 x rayed for porosity and cracks(inside) they were perfict if was a fatige crack inside it would of showed up

Sounds like you have mixed up set is all. Don't blame Brooks, I have bought dozens of set's, there great rods.
I'd buy 6 sets at a time.

I've used the 65 and 88 rods, they will make em any length you want.