[OrangPeEL]

Many of us have a redrilled SBC F-bracket to solve lower mounting of our GM SI series alternator conversion; many variations and tweaks of an upper bracket have been discussed on this site. Here's MY upper "distributor reach-around Opel/SBC hybrid" from 2005- functional, but not something I've been proud of (especially of how I "milled" down the larger 12SI fan for bracket clearance)!

The mounting boss offset difference of a GM SI series alternator appears to be a common swap hurdle we share with some other vintage import makes. This got me thinking about just moving the upper SI boss. Fast forward to summer 2013, I bought a swapmeet 10si and 12si for test fitting my "thoughts". Pictured below is my "boss relocator". A typical modified F-bracket holds lower alt; upper is now mounted with stock Opel upper bracket, stock belt size, and a 12si w/unmodified fan diameter.

Not a game changer here, just another option that works. For me: no fan clearance issues, much more solid...and IMO 50% less wonkiness! :veryhappy

 

[OrangPeEL]

Are these available? :haha:

Sort of...at yer hardware store in DIY config.:haha:

Pretty much = 7" of 3/16"x1"; bend in middle; weld in cross brace and a female thread to end; drill hole.
If you can modify a lower SB F-bracket to fit an Opel- and then mend it stronger after it breaks the first time- you can handle this ~easy.