This is one of those "while I'm in there" situations.

I ordered a set of Woods 555 cams for my 07 Ultra and am planning to use the stock pushrods.

I have everything disassembled and started thinking since I already have the top rocker box covers off that it may not be much more trouble to go ahead and change the cylinders and pistons or heads. Is this a resonable assumption?

Here's a couple options I'm kicking around. I only have funds for one or the other at this time.

1) Change the stock 96" cylinders / pistons to 103" using 16546-99 cylinders and 21996-07 pistons. With stock heads I think this will give me 10.0:1 compression... right?

2) Leave the 96" cylinders and pistons and change the stock heads to 17044-08 SE Pro Kompressor heads. If I read correctly, this combo should put me at 10.3:1 compression.

Of these options, which would yield the most benefit?

I could do the 103" cylinders and pistons now and maybe the heads later or vice versa.

Thanks for your feedback and suggestions.

 

I wouldnt buy different heads I would and will take the stock headers off and send them probably to Big Boyz to have them do the headwork, and install Manual compression relases. If I was in your shoes again I would do the 555 cams, go to a 103, and while you are switching to a 103 send your heads off somewhere Big Boyz does them for 299. and have the whole package done all at once and save yourself the labor charges down the road. If you go 103 make sure you do compression releases others will say you dont need them, I listened to them and I am going to have them installed this winter because I am having a hard time starting.

 

+1 As I was reading the original post I was thinking exactly this!!

If you have Big Boyz (www.bigboyzheadporting.com) do the heads instead of buying the SE heads and have your jugs bored insted of buying new ones... maybe you could swing it all at one time (??) I think this would be a good combonation with the Woods 555's and is the exact build I'm planing when funds are available.

 

On my 08 Street, I had the jugs diamond cut and went from a 96 to a 103, plus put 575 cams in. If you are going to do it, do it all the way...

 

Before making a decision, wait 'til Jamie posts his 107 results. That should be sometime early this week. You may want to copy his build, as he told me it is awesome.

 

Adding some displacement now is a great idea. If you go to 103 with a .030 head gasket into stock heads you're going to wind up pretty darn close to 10:1. Going to 107 nets around 10.2.

 

Send your heads to www.bigboyzheadporting.com, tell Bean what you are putting together and let him work the heads for you.
Send your cylinders to Bean as well, let him bore them out to 103" to match the pistons. He can also provide you with the top-end gasket kit with the .030 head gasket.

It's a waste of money to buy new cylinders and new heads.

Steve