Are the cylinder heads interchangeable on cat 3408 99u DI and 3408b 99u DI and 67u DI Both engines have never been altered from new oem.. and are the inflame kits the same for all bearings pistons and rings? I am working on engines with no arrangement numbers, because I want to buy a 67u and swap parts if I can. I know the 99u is for marine and 67u is industrial but most parts look to be the same.
Arrangement & engine serial numbers are a must--could have different compression ratios, so a comparison of all parts & part numbers will be required first.
Too many options to even list unfortunately. Each engine would have to be done on a case by case basis starting with a Serial Number. In the case of an engine "altered from new OEM" it would have to be stripped down and part numbers taken from components like pistons, crank, camshaft, etc, etc, then supply a S/N of any potential donor engine. Otherwise flip a coin to decide whether or not parts from engine 67Uxxxxx might fit into 99Uyyyyy. TBH it might be a better option.
Give us the cylinder head part numbers and I can look up the Cat Numerical Parts Record on my microfiche and find the serial number fitments for each head part number. Scroll down the webpage linked below and you will find the serial number fitments for the 9Y7212 3408 cylinder kit. There's likely to be other cylinder kit part numbers for different serial number ranges. Caterpillar Cylinder Kit, 9Y7212LK Includes piston, rings, liner, liner seals, pin, retainers. 9 Degree Taper Rod, 5/32 Wide Keystone Ring, 15.6:1 Compression Ratio, No Heat Plug www.heavydutypros.com There are many subtle engineering changes between different engine arrangement numbers.