TSCC GS750's - any with aluminum lower triples?

[Chuck78]

Did any models of 1980's GS750's (or 550/650's) have aluminum lower triples like the gs1100's? I picked up an 81 gs1100 triple set for a pair of gs1000 forks to put on a gs750 we're building for my buddy, and confirmed what I thought I spied on eBay - that some of them were aluminum.
I got an ATK 185mmx35mm fork brace with a lot of parts I got, & I could really use to swap my 175 Tarozzi for this & get wider triples for more tire clearance (can't fit my fender on 175's with 110/90-18 on a 2.5 rim). The aluminum lower would be awesome, & go along with the themes of the rest of my bike (shaving weight off everywhere).

Thanks

Chuck