I am no where near as knowledgeable on twin cam performance issues as are about a dozen members on this site, so when I read a thread like this I look at it from the standpoint of basic information shared. I know this is statin the obvious to the two folks who have posted on this thread so far, but to anyone else reading this who MIGHT not be aware, the 110 kit involves pullin your motor from the frame, disassembling the motor, boring the cases for the larger cylinders (hoping they get all the machined aluminum debris out of all the oil passages) Assembling the motor and reinstalling the motor, reinstalling the primary, starter and exhaust FYI, H-D flat rate labor has just removing the primary at 4 hrs. Major labor involved in this upgrade. I would guess somewhere around $2,500 at most shops. Add to that the cost of a PC or SERT and dyno time and you're looking close to $6,000 in the face to do this upgrade. A Stage II 1690 kit involves no engine removal hence no primary,starter disassembly and reassembly AND the kit without mufflers can be had for $899 list. Add in a set of nice heads and you're still below the cost of the 110 kit. OR if you read the different threads on performance issue, buy individual parts and put together your own HiPo 103 for 1/2 the cost of a 110.
Again, this is for someone who MIGHT not know. The 2007 model H-D's are 96" motors with the same stroke (4-3/8") as the 03-06 103's and the 07 110's so you don't need to do flywheels etc to get to 103. If you have an 06 or older twin cam 88, you need flywheel etc etc . be cheaper to buy a crate 103 and drop in in your frame than build up an 88. IMO
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