Couple quick questions maybe you LSJ guys could answer for me.

Are the LSJ and the LE5 crank pulleys the same diameter or am I looking at different blower speeds between these two pulleys.

Can the LSJ alternator be used on the LE5 SC swap or do I just use the LE5 alt/pulley, as I understand the LSJ alt pulley is clutched?

What is the length of the belt being used with a 2.9 pulley on the LSJ so that I may order a 5 rib belt to match the 5 rib setup for the LE5 presuming im not converting it to all 6 rib pulleys.

 

try posting n the 2.4 section

 

I wish I could remember if they were the same diameter, but I only know they do interchange.

I used the LE5 alt, but it spins backwards with the lsj belt routing. I ordered a 6 rib pulley from Summit/Jegs and installed it on the LE5 alt. Myself and others used the LE5 alt with no problems and reliability is unaffected.

You will need the GM stage 2 belt, so whatever length that is. You're probably going to need to use that and cut a rib off as options for a dual-sided 5 rib are not common iirc. It will work with a 2.9" but if you notice it slipping then you will need to pick up the oversized lsj tensioner pulley from zzp.

I swapped over to 6 rib because of belt slip on small sc pulleys(2.6/2.7). If you pick up a used lsj a/c you can pull off the clutch/pulley and swap it to the LE5 a/c so its 6 rib then you dont need to mess with the a/c system.

 

Crank pulley is a little different; cannot remember...GOOGLE can help
Both alternators will work just fine

Use GM stage 2 belt.
If you have issues, get phenolic spacer(should do it while your doing your SC swap), ZZP tensioner, or oversized tensioner pulley. There is a Gates pulley part number cross reference floating around here

No need for 6rib swap....Im on 2.6" TVS on my stock LE5 and I have no belt slip issues
zzp tensioner, stage 2 belt, phenolic spacer


All these questions could have been answered by a 30second search or just reading Beck's How To