idle pulley spacing

i got myself a block mounted idle pulley bracket.removing blower mounted bracket..due to my front mounted mag drive[bbc summer bros drive]not able to space bracket out far enough...so i need back of idle pulley spaced out 2 3/4" out from my bracket;;is this too much space btween bracket and back side of pulley?

 

Don
With the summer drive I only needed a 3/4 spacer with a RCD block mount idler from memory.

Just FYI