1800 - 1200 = 600
The difference between 750 and 1200 is 450.
22.2222% difference.
The difference is bore size. From the factory they have similar engines, but the 1200 has larger cylinders/pistons.
11.1111% decrease.
2357 - 1157 = 1200
engine # underGEN OR ALT STAND
Somewhere between $900 and $1200. The D700 is a professional-level camera.
The heads,valves, and pistons are different. They also changed carburetors in 1988 to CV, which is the first year for the 1200.
The 1200 is all brass and is an older design. The 1225 is a newer design and is brass and plastic. They are basically interchangeable - however I've read that the 1200 is better in older faucet bodies and the 1225 is better in newer.
The Cost Difference between Invista lycra and Invista elaspan will be approx double the rate. If Elaspan 20-D in local market is 600, then Invista lycra will be 1200 approx.
342 = 1156 which is between 1100 and 1200 and is certainly a square number.
It would look exactly like 1200. You couldn't tell the difference.