Yes, not a magnum. We are building a 91 360 for my son's 71 Valiant 4 door. It is the last year before magnum. Great motor. Hydraulic roller cam and you can bolt any "LA" intake/exhaust parts on it. Let me know if you need an intake....
Nice truck. It looks like you also have the 8 foot box instead of the standard 6 1/2 foot box. Asa should only be allowed to ride in the box because of his :fart:.
Definately change the oil immediately and get the oil level correct. Then the timing chain is a good idea, I like the Edelbrock true roller double rollers available at Mancini Racing. If you use the double roller, you should not use the timing chain tensioner that may be on the engine from the factory, the tensioner is not made to be used with the double roller.
I hope it runs well for you. If not, we can always rebuild the engine (Catoosa Cookout 2013)... We have the technology....