EAS!!!! Driving from CA to TN

Hello everyone I eas from the USMC in mid September and I've convinced my uncle to fly out to California and make the road trip with me. the plan is to hop on rt66 in Santa Monica and stay on it as much as possible to ft. Leonard wood Missouri then cut back down south to my home town McMinnville, TN. 2501 total miles

The car ill be driving is a 1974 Plymouth duster that is pretty much stock and original as far as the engine goes other than a weiand 4 barrel intake and summit carb and headers. I've re done the entire suspension over the past 3yrs with polly bushings, firm feel torsion bars 1.16, bilstein shocks and front sway bar from pst, and hotchkis leaf springs.

So id love to get advice from everyone about how to prep the car, best oil to use, maybe tricks for better mpg lol I average around 12 in the city I don't do a ton of highway driving mostly just up one side of Palomar mountain and down the other. The bare minimum for tools I don't want to be carrying more weight than I need. I've owned the car for 4 1/2 years and put about 15000 miles on it and its never left me stranded so I'm hoping it can do one more big trip before she gets a new heart.

Also share pics and experiences I'm a young guy who loves to learn from others mistakes ha its a lot easier than making my own. thanks for taking the time to read and hopefully post.