How about a TransDapt #2048 , looked at the Offy I have on a motor that uses an Edelbrock 500 and if I remember correctly I used one of these to raise the carb 2" and the bolt pattern should also fit your Holley carb.,

Last edited by jalopy45 #4899; 02/12/11 06:43 PM. Reason: add
'45 Ford PU
66 Valiant wagon, leaning tower of power.
79 Chevy C10 w/250
02 PT Cruiser Convertable