If your shifter is on the column you have an SE. Changing it would be a lot of work, and require more time/money then it'* worth.
A lot of bad luck has hit you, hopefully this new engine is the charm. Synthetic isn't the best if you have a lot of stuff in the oil system like dirt holding it together. If you use synthetics their detergents may wash out that gunk, and leave holes that have been plugged by dino oil. Every oil system is different, and no one can tell you for sure if it'* good or bad to switch.
'06 Vee Dub GTI 2 door Tornado Red
- 2.0 Turbocharged, Intercooled, Direct Injected, 6 Speed DSG, Underbody Aero, 17" Classix
- Moonroof, Bi-Xenon headlamps, Interlagos Plaid Sport Seats, 6 Disc In-dash, iPod integration, GTI Monster Mats (winter)
'93 Bonneville SE Purple Pearl H4U package - picked up June 23, 2003, Traded-in June 28, 2007...