This area explains the difference between the year range of the drag pipes made by MAC products that we sell for Japanese CB750 Honda's and how they can be adapted to further years of the CB750 '79 and later.

The difference between the two year spreads are as follows.

69-'76 is designed for the CLAMP-ON flanges. Where you have a spicut that hangs
 out of the exhaust port and the new pipe slips over the spicut and is clamped into
 place with a stock diffuser type clamp.

77-'78 is designed to work with the conventional BOLT-ON type diffuser rings.
The pipe goes directly IN the exhaust port and there are two half collars and a diffuser
ring that are installed to hold it in. The diffuser mounts with two large studs or bolts.

CUSTOMIZING AND ADAPTION TIPS BELOW

If you are adapting to another year of CB750 then you will need to attain the
hardware for the correct year.

We have had people adapt the '77-'78 Drag Pipes to later years of CB750 '79-'83.
The best way to adapt the mount is to attain '77-'78 CB750 half collars (8 of them)
and use the original '79-'83 exhaust difffuser rings.

The rear mounting (hangar) bracket will also need to be adapted for use on some 
'79-'83 models. Please do not consider if you do not know how to make your own hangars.

They can not be adapted to ANY other size or year that we know of. They do not fit CB500/CB550/CB650.