newschool72

iTrader: (12)

Im thinking about a 25% UDP for my birthday in a couple weeks, but Im running into a little confusion. My LS3 has the vette front drive setup. Am I right in thinking the c5, c6 LS1, LS2 and LS3 all have the same offset on the crank pulley and interchange? That's what I am gathering by my research, but Summit doesn't show the C6 LS3 on the app chart. It just goes up to the 06 LS2.

speedtigger

iTrader: (16)

I don't know the answer to the offset question, but I have read from some engine builders who say do not use the 25% pulley. If you have to use underdrive, use the 10%. The 25% supposedly does not have enough mass to effectively dampen the harmonics.

I have the Vette accessory system on my car, but it was the LS2 style. I would think they are the same, but I am not sure.

Oh, and one more thing, ATI for the win!
http://www.atiracing.com/products/da...s/damchevy.htm

ATI lists the LS3 with the LS2 and LS6

http://www.summitracing.com/parts/at...9/applications

newschool72

iTrader: (12)

Thanks Tigger. I had seen a couple companies that listed them all together. I just needed some more confirmation before I pulled any triggers.

Doug G

May also need to change the pulley on the alternator so it charges at idle as well (like stock)....found out the hard way on the old 406ci SBC

newschool72

iTrader: (12)

Yep, got the Tshirt on that one as well. I have the whole March UDP setup on my 406, LOL. Most that I have looked at claim 900rpms will give full charge with the vette alt. I idle at 850 now, so a bump to 900 shouldn't cause any issue.