Yes, you will need the thundermax or other (power commander, TTS, etc.) to be able to put a good tune to run the motor right.

So far I have about 1,100 miles on my stock clutch that has been on my 96" for VERY hard 12,000 miles and has yet to slip w/ just having the SE heavy clutch spring.....my guess is that it will probably go soon, but she is holding.

 

ok good to know on the clutch. ive got 11,500 miles on my bike. the first owner never rode it i guess lol.
I acked and groveled over a tuner and just decided on the thundermax one day. it runs great for now so next year ill buy one from ebay or something for a good price.

 

The S/E throttle body I have is the 58mm, not the 50 (came with my stage 4 kit). MSRP for the kit is $1995, but I got mine on sale for I think $1700 and that kit comes with new jugs, 58mm T/B, high flow injectors, perfect fit pushrods (I went with adjustable), complete set of cnc machined heads, manifold, S/E tuner, clutch spring, 10:5:1 pistons, complete set of gaskets and cams. While apart I changed all the bearings out, added the S/E compensator, roller rockers and S&S lifters. Did all the work myself and was done in three days. Would have been quicker if I didn't have to find a bearing puller and didn't have to stop to do family stuff. Just get a manual and you're set. Save that money on labor and buy the wife something You will have to get it tuned, but our local shop can put a base tune in until then...

Now granted it's not a 107, but it still gives me 110 horses of fun.