What camshafts would be nice?

[robokill]

ok first off 48 mm itb's are to big. It will cost you power instead of deliver more.

Ok cams, forget low lift. If you want a good engine you will be looking at 10mm plus lift cams. Apardal hit the spot with the cams. It will keep the max RPM lower which will keep the engine reliable.

A high revving engine will need more maintaince and will break sooner. What is your base to start with?

As I reckon it will be either 3 or 7 ribbed lower block with a 40mm crank and 18mm piston pins. In that case try to keep the RPM's as low as possible.

If you want a high revving engine, start by getting a 42mm cranks with rods of 20mm piston pin. Also make sure you have an non overbored engine. This could increase the lifespan if you have any issues that you can still overbore it.

As lowering the deck on the lower block or shaving the head isn't a good option. You will be looking at new pistons and a 0.8mm headgasket that should get you somewhere around 12.

You will probably be looking to spent aorund 2000 on the bottom end if you get the work done. Don't forget to clean the crank counter wehights and polish the crank journals. Clean the lower block and clean the oil canals for better flow.