New Drive belt. High RPM

[F500-92]

I just installed a new belt and now the RPMs are really high.  The dimensions seems the same as the original.  Dayco 59011-3502D. The Dayco is 46 5/8".  1/8" Longer than the LM752 below so I moved the jackshaft forward a bit.      The LM572 is sitting higher in the Secondary than the old dayco I took off as well.

Not sure where to go from here.

Parts Unlimited LM572
dimension   1 1/4" x 46 1/2"
finish   Raw
length   46 1/2"
made in the u.s.a.   Yes
material   Textile
model   Performer
specific application   Yes
style   Performance Replacement
type   Drive Belt
width   1 1/4"

[Vader440]

If you moved the jack shaft toward the engine, that would make the belt even longer in comparison to the original. you may need to move it back toward the fuel tank.