18,000 orig. mile 318 build

Went to the local U Pull It and picked up a pair of '93 mag. exhaust manifolds along with a few other odds n ends. I also came across 8.25 rear out of a 74 charger. I didnt purchase it but was debating, for i can probably snap it up cheap. Whats your thoughts? Ill prolly run my 7.25 until winter but really wanna put some smoke to it for next sping.