Okay had to look for this again
http://hondachopper.yuku.com/topic/2755#.VBxjTfkbZfcIt's a list of bikes sorted by the size of the bearings used in the frame neck. So here are all the bikes that could possible interchange with the 79-82 750C/K/F (Upper: 26 x 47 x 15, Lower: 30 x 55 x 17 ). According to this, you could take the entire front end off a GL1100 and bolt it right on to the 750 (triple clamps, forks, wheel and all):
Upper: 26 x 47 x 15
Lower: 30 x 55 x 17
Honda NSR250R/F
Honda VTR250 (89-91)
Honda CBR400R (87)
Honda CBR400 R/R
Honda NS400RF/RG (85-86)
Honda VFR400ZG/RG
Honda CMX450C (86-87)
Honda CX500TC (82)
Honda VF500C (84-85), VF500F (84-86), VF500FE/FIIE/FF
Honda VT500C (85-86)
Honda CBR600 (89-90)
Honda CBR600F (87-90), CBR600 FM-FR (91-97), CBR600H
Honda VT600CJ (87), VT600C N-R (92-94)
Honda VT600C/CD Shadow VLX (88-97
Honda CX650T (83)
Honda NT650 (88-89)
Honda NT650J Revere
Honda CB700SC (84-86)
Honda VF700C (84-87)
Honda VF700F/S (84-85)
Honda VFR700F/F2
Honda CB750C/F/K (80-82)
Honda CB750F N-S (92-95)
Honda CB750FA/FB/FC/ F2C
Honda CB750SC (84-85)
Honda CBX750FE/F2F (84-86)
Honda VF750C (82-83)(8Cool
Honda VF750CC/CD/CE/SC/SD
Honda VF750F (83-84)
Honda VF750 F D/E/F (83-85)
Honda VF750FD
Honda VF750S (82-83)
Honda VFR750 (90-93)
Honda VFR750F/F2 (82-87), VFR750F L-S (90-95)
Honda VFR750FG/FH/FJ/FK/ FL
Honda VT800 (88-89)
Honda VT800C Shadow(8Cool
Honda PC800 Pacific Coast (89-9Cool
Honda CB900C (80-82), CB900F A/B/2B/C/2C (80-82), CB900FS(94)
Honda CBR900RR (93-9Cool
Honda CB1000C (83), CB1000F S (95)
Honda CBR1000 (87-93)
Honda CBR1000F (87-8Cool(90-96)
Honda CBX B/C (81-82)
Honda VF1000F (84-85), VF1000FE/FF/F2F, VF1000R (85-86)
Honda GL1100 (80-83), GL1100C/AC/DC/IC, GL1100D2D/AD/A/IA/DA,
GL1100RB/RC/D/ID/DD
Honda VF1100C (83-86), VF1100S (84-85)
Honda VT1100C (85-89), VT1100C R-S (94-95)
Honda GL1200 (84-87)
Honda GL1500 (88-91)
Honda GL1500 AP-AR (93-94)
Honda VTX1800C (02)
89 VN 750A - Given to son-in-law
79 CB 750K-sold 3 May 21
78 CB 750K
77 CB 750K
77 GL 1000 x 2
77 CB 550F
Holton, KS, US