GT380 model year cylinder differences

[jabcb]

I’ve had a 1972 GT380 project bike for a while.
Took a look at it while I was moving things around to get the mower out & put the snow blower away.
Per the VINs, I have a 1972 model frame & 1974 model crankcase.

When 100% correct, the 72/73 models has individual carbs & the 74+ models have a bank of carbs.
My bike has the individual carbs.

The cylinders are also different.
So , how can I tell if I have 72/73 model cylinders or 74+ model cylinders?
Does it make any difference?

[Alan H]

I’ve had a 1972 GT380 project bike for a while.
Took a look at it while I was moving things around to get the mower out & put the snow blower away.
Per the VINs, I have a 1972 model frame & 1974 model crankcase.

When 100% correct, the 72/73 models has individual carbs & the 74+ models have a bank of carbs.
My bike has the individual carbs.

The cylinders are also different.
So , how can I tell if I have 72/73 model cylinders or 74+ model cylinders?
Does it make any difference?

Lots of details and pics HERE

Basically the early ones were similar to the 550, with separate carbs and different finning to barrels and head. When they went to linked carbs, they shortened the barrel/head fins adjacent to the carbs, and also moved the fuel tap forward so it's a different tank. The ramair cowls changed too. I don't think the crankcases changed regards porting so all barrels should fit. I can't find my 380 parts catalogue to confirm this though.

[jabcb]

Thanks.

Looked on eBay to see the differences. Difference is easy to spot when looking at the fins near the carbs.
Pic with 72/73 cylinder on left & 74+ on right:


My bike has 1974 model crankcase, 74+ model cylinders & 72/73 model carbs.

[Mencie]

I owned a '72 380 for many years.

When sourcing parts, I was reliably informed that the porting on the 72 and 73 models was softer than later ones.