S&S CYCLE SKU: T14-664035

S&S Cycle Cylinder Heads — 2006-2012 Harley-Davidson Dyna 91cc

$1,855.95
Free shipping on orders $99+ · Best value guarantee
From $154.66/mo with Affirm. See if you prequalify
OUT OF STOCK
Free Shipping on orders $99+
Best Value Guarantee
30-Day Returnssee policy
Authorized Dealer — sourced direct
NOT SURE ABOUT FITMENT?

S&S Cycle cylinder heads for 2006-2012 Harley-Davidson Dyna 91cc engines, featuring a 4-1/8" bore and stock bolt pattern for direct replacement. Cast in wrinkle black finish with .650" steel construction and -.064" milling for precise compression and performance.

Features

  • 4-1/8" bore diameter
  • Stock bolt pattern — no adapter needed
  • Wrinkle black finish
  • 91cc displacement
  • Steel construction

Specifications

  • Brand: S&S Cycle
  • Manufacturer Part #: 900-0993
  • Displacement: 91cc
  • Bore: 4-1/8"
  • Finish: Wrinkle black
  • Weight: 28.65 lb
  • Category: Engine Components / Heads

Fitment

Fits 2006-2012 Harley-Davidson Dyna models with 91cc engines. Stock bolt pattern ensures direct bolt-on installation without adapters.

Frequently Asked Questions

Will these heads fit my 2013+ Dyna?

No — these are engineered for 2006-2012 Dyna 91cc engines. Later model years require different head specifications.

Do I need to upgrade my pushrods or rocker arms?

Verify pushrods and rocker arm compatibility with S&S or your builder — this depends on your complete engine build.

What's the compression ratio with these heads?

The -.064" milling surface is specified by S&S for use with matching pistons and cams. Consult S&S or your engine builder for your exact compression target.

Is installation a bolt-on job?

Stock bolt pattern allows direct bolt-on replacement, but professional engine assembly is recommended for proper torque specs and gasket sealing.

BRANDS&S Cycle
TYPEHeads
SKUT14-664035
WEIGHT28.65 lb
Please contact us to confirm fitment for your specific motorcycle, or check the product title for compatibility notes.
CUSTOMER REVIEWS
4.8
5 RATINGS
5★ 4
4★ 1
3★ 0
2★ 0
1★ 0
✓ VERIFIED
Oct 15, 2020

I ride a 2013 blackline. There is no doubt s&s makes a quality product. But what I didn’t know at the time is the bike has stock apr (auto pressure release). That being said the stock apr’s do not fit In s&s heads. So these are not a direct swap. Solution is buying there apr kit which will cost you around $400 plus (also have to rewire it ) different rocker covers that will cost you another $1000 bucks. I got lucky and had easy start cams so I just deleted the stock apr and turned off that setting in my tuner. I have a thundermax so it was easy for me. Stock computers or different tuners might be more of a pain in the ass. <br /><br />Overall they are a quality product but imo they should change that design to allow the stock apr’s. All that extra time and money because there made the apr port larger.

— Anonymous
✓ VERIFIED
Feb 15, 2022

I did a 107 big bore bike ran about 235 degrees, then I installed these heads bike now runs at 275 degrees, it runs hot now, I’m installing an oil cooler, the bike goes from 0 to 60 in 3 seconds. It’s hard to hold on at full throttle my face shield presses against my face the power is unreal!

— Anonymous
✓ VERIFIED
Jan 17, 2012

Fitment was good, but you have to rework the breather passages in order to use stock rocker boxes. Also don't forget the longer head bolts.

— Anonymous
✓ VERIFIED
Mar 13, 2025

Drop-in replacement that exceeds OEM performance.

bought a set of these for a just completed 117" engine upgrade. They do offer better all around performance. Other than having to install a set of manual compression releases. They can be considered a true drop-in replacement. Using a set of 0.030" head gaskets will get you a calculated compression bump to ~10.7:1 from 9.2:1. They are billet and not cast.

— David H
✓ VERIFIED
May 28, 2021

They got here fast and they are just what I needed to finish my 110 kit.

— Anonymous