I want to shoot them I shoot POC 32" arrows and currently a 125gr 2-blade Magnus head, shafts are 65-70# how much difference would this affect the arrow with that much weight upfront on my long shaft. And do Hill heads penetrate good. The 160 gr.My longbow is @ 60#@ 31" draw weight.Thanks for any help you give.

Are you drawing 31 inches?  If so, even the 65-70# shafts are about at their limit.  They may handle the heavier heads and they may not, depending on how center shot your bow is.  You might need to go up another five pounds, maybe even10 if you go to the 160 grain heads.  Or, you could build out your side plate a little.    By the way, my "160" grain Hill heads before sharpening are all closer to 175 grains.

Tim,
  I'm one of the few that use these heads and for a large head they fly true without any windplaining. For myself I found that I didn't really have to make any adjustment between my field points and the Hill head.Once you have them sharp they will blow through any animal that you may encounter in the lower 48. When I weighed the new heads they were between 176 grains and 179 grains, but when sharp they were down to 163 grains + or - 1 grain. Hope this helps.

Rick

I am @31" you think I should go to 80-85# spice and that may be enough.

You can compensate for the weakening of your shaft's dynamic spine, if any, buy building out your sideplate a little. Mount 'em up and shoot 'em.

Thanks I think I will give it a shot!

Definitely try building out the side plate before buying new arrows, could be a simple and cheaper fix. You can always buy new arrows in the future if the side plate doesn't work.

The Hill heads are extremely forgiving.  Minor tuning tweaks such as suggested above will likely be more than enough.  

Have taken last two mulies with Hill heads.  Had to work to get them really sharp, but they perform very well.  I have lots of confidence in them.

If your LB is a traditional style with minimal backset, 60# at your draw, then start by adding 5# for every inch over 28" of draw lenght, and 5# for every 25 gr. in added tip weight above 125 gr. That comes out 15# + 5 to 10# for wt. which is approximately 20-25# in spine, or 80 - 85#. However, it is possible that lighter spined shafts will work for you, much depends on your setup and shooting style.

If you are shooting a reflex-deflex, with non-stretch string material, or lower string count you will need to up the spine. It will be hard to find heavier spined shafts, but not impossible.  

It is important to mount the nocks perpendicular to the grain in the shaft giving you the stiffest and most consistent reading. Tapered shafts will also help with arrow flight.

Personally, I dropped from a 30" draw shooting a recurve to 27.75" with a longbow.  I shot better with a relaxed style, slightly bent elbow and lower grip. Hill was tall and shot with a 28" draw length.

I think Santa will have some Hill heads to drop off at my house will let guys know how they work out.