03SOHCOK

Yes, the pulleys are piggyback style. Their SUM-C2511 has SFI balancer is $160, but another $10-40 gets the brands recommended above. I think that all of the sets closer to the $100 mark will be the same. I wish they'd all verify that in their description/specs...some do. The set I received simply did not fit on the crank snout. Good luck with whatever set you decide to go with!

Sxynerd

Underdrives are NOT worth it unless they are steeda and they are under $100 AND you don't plan on F/I.

Tim99GT

+100,

I have a set of BBK that ill sell you for $50

Sxynerd

^ I just couldn't imagine paying $200+ for 4-6hp in the UPPER RPM's. Hell, dyno +/- is greater than the number of Hp gained from the mod. Not worth it to me.

Mustang_NTriangle

CMS stage 2.5 cams will clear just fine; hell even stage 3s don't require flycut pistons. So go with 2.5 cams. Don't buy them twice and if you are ever thinking going F/I but the 2.5 blower cams they will work na as well.

03SOHCOK

Well, I think that checking the clearance is good practice anyway, particularly if they are debatably close. It is promising to know that even the larger cams could work. I don't know if/when it will see any boost or spray. My limited research says the rods aren't super stout, but we see these glory builds on them all the time. More than anything, I just want to get this Mustang to be less of a slouch, and more of a "muscle car" or "sports car".
So in the mean time, what to do next...throttle body/plenum, MAF, gears? Gears will be the most noticeable gain I guess...that would expedite a programmer as well.

mrtstang

I agree in checking for ptv clearence. In fact i have done a ton of research in this area (about to do cams myself). Basically if you have the stock pi heads and pistons, you'll be suprised how little room there might be. Obviously with certain aftermarket heads you'll have more clearence.

nickmckinney

Have you actually measured these clearances? I found 0.005" with VT/CMS Stage 2 cams installed at a 108 intake centerline with a stock PI motor. With a cam gear advanced 2 degrees the valves would have been deep in the piston. The stock Ford gears are plus or minus 4 degrees BTW.

mrtstang

+1! John Tymensky of Modular Performance (out here in MI) showed me the stock pi head 2 valve pistons, compared to the stock npi head pistons. The pi pistons were actually thicker...thus obviously creating less room for bigger cams! He also went on to say that the way the piston sits inside the head causes less clearence as well!

Combine that with the possibility of the stock cam gears being +4 to -4 degrees off, and it starts to look a little scary!